CVE-2026-74667

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74667", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.924Z", "datePublished": "2026-08-22T15:32:38.862Z", "dateUpdated": "2026-10-16T19:16:08.261Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:21.641Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: reset the MAC header on the packet-socket transmit path\n\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\n\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\n\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\n\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The flaw is reached only via local AF_PACKET transmit syscalls (sendmsg on SOCK_DGRAM/bound SOCK_RAW with PACKET_QDISC_BYPASS); remote network input cannot trigger packet_parse_headers() on this TX path.\nAC:L - The attacker controls socket type, enables PACKET_QDISC_BYPASS via setsockopt, selects a vulnerable netdev (macsec/macvlan/tap), and sends frames to reliably hit dev_direct_xmit() without races or external victim state.\nPR:L - packet_create() requires CAP_NET_RAW, which unprivileged users commonly obtain inside user+network namespaces (unshare -Urn) per kernel capability rules, not solely real root in the init namespace.\nUI:N - Exploitation requires only the attacker opening a packet socket, enabling bypass, and transmitting; no victim user action such as opening files or mounting filesystems is needed.\nS:U - Impact is kernel heap/slab disclosure and transmit-time corruption within the same kernel security authority; it is not a VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:H - Unset mac_header makes eth_hdr(skb) a large out-of-bounds kernel memory read (~64 KiB past skb->head); macsec KASAN confirmed slab data leakage and bytes can be emitted on the wire in the frame.\nI:H - Affected TX drivers consume the bogus eth_hdr() pointer to modify skbs (e.g., macsec memmove of OOB MAC bytes into the frame, vxlan header rewrites), giving attacker-influenced corruption beyond a pure read.\nA:H - The invalid mac_header dereference can fault or trigger KASAN/driver failures during ndo_start_xmit(), causing kernel oops/panic or repeated transmit failure on the bypass path."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/packet/af_packet.c"], "versions": [{"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "1e43a1d66615f411d427f9df1f46dd049d9e3681", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "4057853a91fb796c4f47c7d1baf1aa085394148e", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "2610ed4e86a4590234a9d70518c469751c5af231", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "b47ba8fe6e1d2df8c92048de5afafd059447dc30", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "971aa7d99242bbf09513e27b7a243f0b29ff23ae", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "fdd4d7d52358a58e351dd9d82530c04eba8ccd7a", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "c2707480cfbf19c7619acc9c089d17f20869821f", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/packet/af_packet.c"], "versions": [{"version": "5.1", "status": "affected"}, {"version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.152"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.104"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681"}, {"url": "https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e"}, {"url": "https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231"}, {"url": "https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30"}, {"url": "https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d"}, {"url": "https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae"}, {"url": "https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a"}, {"url": "https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f"}], "title": "net/packet: reset the MAC header on the packet-socket transmit path", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74667", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:14.644201Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:08.261Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74667", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.924Z", "datePublished": "2026-08-22T15:32:38.862Z", "dateUpdated": "2026-10-16T19:16:08.261Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:41:21.641Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: reset the MAC header on the packet-socket transmit path\n\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\n\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\n\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\n\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The flaw is reached only via local AF_PACKET transmit syscalls (sendmsg on SOCK_DGRAM/bound SOCK_RAW with PACKET_QDISC_BYPASS); remote network input cannot trigger packet_parse_headers() on this TX path.\nAC:L - The attacker controls socket type, enables PACKET_QDISC_BYPASS via setsockopt, selects a vulnerable netdev (macsec/macvlan/tap), and sends frames to reliably hit dev_direct_xmit() without races or external victim state.\nPR:L - packet_create() requires CAP_NET_RAW, which unprivileged users commonly obtain inside user+network namespaces (unshare -Urn) per kernel capability rules, not solely real root in the init namespace.\nUI:N - Exploitation requires only the attacker opening a packet socket, enabling bypass, and transmitting; no victim user action such as opening files or mounting filesystems is needed.\nS:U - Impact is kernel heap/slab disclosure and transmit-time corruption within the same kernel security authority; it is not a VM escape, IOMMU bypass, or other cross-boundary scope change.\nC:H - Unset mac_header makes eth_hdr(skb) a large out-of-bounds kernel memory read (~64 KiB past skb->head); macsec KASAN confirmed slab data leakage and bytes can be emitted on the wire in the frame.\nI:H - Affected TX drivers consume the bogus eth_hdr() pointer to modify skbs (e.g., macsec memmove of OOB MAC bytes into the frame, vxlan header rewrites), giving attacker-influenced corruption beyond a pure read.\nA:H - The invalid mac_header dereference can fault or trigger KASAN/driver failures during ndo_start_xmit(), causing kernel oops/panic or repeated transmit failure on the bypass path."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/packet/af_packet.c"], "versions": [{"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "1e43a1d66615f411d427f9df1f46dd049d9e3681", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "4057853a91fb796c4f47c7d1baf1aa085394148e", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "2610ed4e86a4590234a9d70518c469751c5af231", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "b47ba8fe6e1d2df8c92048de5afafd059447dc30", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "971aa7d99242bbf09513e27b7a243f0b29ff23ae", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "fdd4d7d52358a58e351dd9d82530c04eba8ccd7a", "status": "affected", "versionType": "git"}, {"version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "lessThan": "c2707480cfbf19c7619acc9c089d17f20869821f", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/packet/af_packet.c"], "versions": [{"version": "5.1", "status": "affected"}, {"version": "0", "lessThan": "5.1", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.10.265"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "5.15.216"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.1.183"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.6.152"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.12.104"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.1", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681"}, {"url": "https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e"}, {"url": "https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231"}, {"url": "https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30"}, {"url": "https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d"}, {"url": "https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae"}, {"url": "https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a"}, {"url": "https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f"}], "title": "net/packet: reset the MAC header on the packet-socket transmit path", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74667", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:14.644201Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:14:15.334Z"}}]}}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/packet/af_packet.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1e43a1d66615f411d427f9df1f46dd049d9e3681", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "4057853a91fb796c4f47c7d1baf1aa085394148e", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "2610ed4e86a4590234a9d70518c469751c5af231", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "b47ba8fe6e1d2df8c92048de5afafd059447dc30", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "971aa7d99242bbf09513e27b7a243f0b29ff23ae", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "fdd4d7d52358a58e351dd9d82530c04eba8ccd7a", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}, {"lessThan": "c2707480cfbf19c7619acc9c089d17f20869821f", "status": "affected", "version": "75c65772c3d18447d62d3aca5f91b06c16cc25e4", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/packet/af_packet.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.1"}, {"lessThan": "5.1", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.265", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.216", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.183", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.152", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.104", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: reset the MAC header on the packet-socket transmit path\n\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\n\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\n\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\n\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet/packet: restablecer la cabecera MAC en la ruta de transmisi\u00f3n del socket de paquetes\n\npacket_parse_headers() restablece la cabecera MAC solo para una trama SOCK_RAW cuyo socket no vincul\u00f3 un protocolo. Un socket SOCK_RAW vinculado a un protocolo, cualquier trama SOCK_DGRAM y la ruta SOCK_PACKET heredada, por lo tanto, dejan skb -> mac_header sin establecer aqu\u00ed.\n\nPara las tramas enviadas a trav\u00e9s de __dev_queue_xmit() esto es inofensivo: restablece la cabecera MAC incondicionalmente. Pero la ruta PACKET_QDISC_BYPASS del socket de paquetes utiliza dev_direct_xmit(), que no lo hace, por lo que la trama llega a ndo_start_xmit() con la cabecera MAC sin establecer. Un controlador que lee eth_hdr(skb) en la transmisi\u00f3n luego desreferencia skb -> head + (u16)~0, un acceso fuera de l\u00edmites ~64 KiB m\u00e1s all\u00e1 de la cabecera -- la misma clase corregida para un consumidor en el commit f5089008f90c ('macsec: no leer una cabecera MAC sin establecer en macsec_encrypt()').\n\npacket_parse_headers() se ejecuta solo en la ruta de transmisi\u00f3n, donde skb -> data apunta al inicio de la cabecera L2 para cada tipo de socket de paquetes, independientemente de su longitud: SOCK_RAW y SOCK_PACKET llevan una cabecera proporcionada por el usuario y SOCK_DGRAM tiene una construida por dev_hard_header(). Restablecer la cabecera MAC incondicionalmente, reflejando __dev_queue_xmit(), para que la trama tambi\u00e9n est\u00e9 anclada en la ruta de bypass.\n\nEncontrado por 0sec (https://0sec.ai) utilizando an\u00e1lisis de c\u00f3digo fuente automatizado; verificado contra el c\u00f3digo fuente y emparejado con el informe KASAN de macsec en f5089008f90c. Compilado y probado."}], "id": "CVE-2026-74667", "lastModified": "2026-10-16T20:17:50.750", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74667", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:14:14.644201Z", "version": "2.0.3"}}]}, "published": "2026-08-22T16:16:40.580", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1e43a1d66615f411d427f9df1f46dd049d9e3681"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2610ed4e86a4590234a9d70518c469751c5af231"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4057853a91fb796c4f47c7d1baf1aa085394148e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/971aa7d99242bbf09513e27b7a243f0b29ff23ae"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b47ba8fe6e1d2df8c92048de5afafd059447dc30"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c2707480cfbf19c7619acc9c089d17f20869821f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/fdd4d7d52358a58e351dd9d82530c04eba8ccd7a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net/packet: reset the MAC header on the packet-socket transmit path", "id": "2521490", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521490"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-824", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet/packet: reset the MAC header on the packet-socket transmit path\npacket_parse_headers() resets the MAC header only for a SOCK_RAW frame\nwhose socket did not bind a protocol. A protocol-bound SOCK_RAW socket,\nany SOCK_DGRAM frame, and the legacy SOCK_PACKET path therefore leave\nskb->mac_header unset here.\nFor frames sent via __dev_queue_xmit() this is harmless: it resets the\nMAC header unconditionally. But the packet-socket PACKET_QDISC_BYPASS\npath uses dev_direct_xmit(), which does not, so the frame reaches\nndo_start_xmit() with the MAC header unset. A driver that reads\neth_hdr(skb) on transmit then dereferences skb->head + (u16)~0, an\nout-of-bounds access ~64 KiB past the head -- the same class fixed for\none consumer in commit f5089008f90c (\"macsec: do not read an unset MAC\nheader in macsec_encrypt()\").\npacket_parse_headers() runs only on the transmit path, where skb->data\npoints at the start of the L2 header for every packet-socket type\nregardless of its length: SOCK_RAW and SOCK_PACKET carry a user-supplied\nheader and SOCK_DGRAM has one built by dev_hard_header(). Reset the MAC\nheader unconditionally, mirroring __dev_queue_xmit(), so the frame is\nanchored on the bypass path too.\nFound by 0sec (https://0sec.ai) using automated source analysis;\nverified against source and matched to the macsec KASAN report in\nf5089008f90c. Compile-tested.", "A flaw was found in the Linux kernel's networking packet handling. Specifically, the `packet_parse_headers()` function does not consistently reset the Media Access Control (MAC) header for certain packet types on the `PACKET_QDISC_BYPASS` path. This can lead to an unset MAC header, causing a driver to perform an out-of-bounds read when processing network frames. This memory corruption vulnerability could result in system instability or a denial of service."], "name": "CVE-2026-74667", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74667\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74667\nhttps://lore.kernel.org/linux-cve-announce/2026082229-CVE-2026-74667-8fdf@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,1e43a1d66615f411d427f9df1f46dd049d9e3681)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,4057853a91fb796c4f47c7d1baf1aa085394148e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,2610ed4e86a4590234a9d70518c469751c5af231)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,b47ba8fe6e1d2df8c92048de5afafd059447dc30)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,284f3e7a3f1a743fdf89e304fd1f19d5ffcff46d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,971aa7d99242bbf09513e27b7a243f0b29ff23ae)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,fdd4d7d52358a58e351dd9d82530c04eba8ccd7a)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[75c65772c3d18447d62d3aca5f91b06c16cc25e4,c2707480cfbf19c7619acc9c089d17f20869821f)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.1"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.1)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.10.265,5.11.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.216,5.16.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.183,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.152,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.104,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.45,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-22T19:00:14.811990+00:00", "updated": "2026-08-25T14:00:17.976881+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}