CVE-2026-74684

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74684", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.926Z", "datePublished": "2026-08-22T15:32:50.846Z", "dateUpdated": "2026-10-30T12:30:16.355Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:30:16.355Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()\n\nThe commit 4f61f133f354 (\"net: tap: NULL pointer derefence in\ndev_parse_header_protocol when skb->dev is null\") fixed a crash in\ntap_get_user() by assigning skb->dev before calling tun_vnet_hdr_to_skb().\nThis is required because virtio_net_hdr_to_skb() may invoke\ndev_parse_header_protocol(), which dereferences skb->dev. Without the\nassignment, a NULL pointer dereference can occur.\n\nHowever, tap_get_user_xdp() still parses the virtio-net header before\nassigning skb->dev. When the vhost TX path passes an XDP buffer containing\na GSO virtio-net header but the protocol is set to zero on purpose,\ntun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb->dev\nis still NULL, resulting in a crash.\n\nFix this by looking up the tap device and assigning skb->dev before calling\ntun_vnet_hdr_to_skb(), matching the ordering already used in\ntap_get_user(). Preserve the existing RCU read-side critical section across\ndev_queue_xmit()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - A malicious KVM guest reaches tap_get_user_xdp() by kicking the virtio-net TX virtqueue; vhost_net handle_tx_copy batches XDP buffers and invokes tap_sendmsg(TUN_MSG_PTR), not via any host network packet-receive path.\nAC:L - On typical QEMU/KVM vhost-net+tap/macvtap backends with TX batching enabled, a guest fully controls virtio-net GSO headers and Ethernet frames; sending GSO with ethertype 0 deterministically hits dev_parse_header_protocol() with skb->dev NULL without races.\nPR:N - No host root or capabilities are required; a malicious cloud VM tenant only needs code execution inside a guest using virtio-net with a vhost-net tap backend, matching other guest-to-host virtio/KVM CNA scores.\nUI:N - No separate victim action is needed; the attacker submits crafted virtio-net TX descriptors from their own guest workload during normal VM operation without requiring host administrator interaction.\nS:C - Guest-supplied virtio-net TX data triggers a NULL pointer dereference in host tap_get_user_xdp(), panicking the physical host kernel and crossing the KVM guest-to-host virtualization security boundary.\nC:N - The failure mode is a NULL pointer dereference at dev->header_ops with skb->dev unset; there is no demonstrated out-of-bounds read, use-after-free, or other memory corruption that could disclose host kernel data.\nI:N - No guest-controlled host memory write or control-flow hijack occurs; the host kernel oopses on the NULL dereference before any exploitable modification beyond the immediate crash.\nA:H - The NULL pointer dereference in dev_parse_header_protocol() provokes a host kernel oops/panic in the vhost worker during guest virtio-net TX, denying availability of the hypervisor and all co-resident VMs."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/tap.c"], "versions": [{"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "1d022885f3e6e0e238815391a4afaf3a4fb0a442", "status": "affected", "versionType": "git"}, {"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "61dd022c55c7307ec119e5672cb141cccbecf3b1", "status": "affected", "versionType": "git"}, {"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "15583b07fd691a844fbf7b3ad612cdc9e9a657c0", "status": "affected", "versionType": "git"}, {"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "8b444b126cd8e4473e652f529753ed4dd1360a9c", "status": "affected", "versionType": "git"}, {"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b", "status": "affected", "versionType": "git"}, {"version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "3874892dd27d5387aa9a06f58d9060f18f351d24", "status": "affected", "versionType": "git"}, {"version": "ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d", "status": "affected", "versionType": "git"}, {"version": "54ef8243c3c8e90f1ea5792e6752e021a25c8eb3", "status": "affected", "versionType": "git"}, {"version": "ca278267d6cd9544645731732455b6b20cb0e895", "status": "affected", "versionType": "git"}, {"version": "faa3baa2828c5e1c4374f3e60041f75c64f5fcb6", "status": "affected", "versionType": "git"}, {"version": "99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748", "status": "affected", "versionType": "git"}, {"version": "4.14.226", "lessThan": "4.15", "status": "affected", "versionType": "semver"}, {"version": "4.19.181", "lessThan": "4.20", "status": "affected", "versionType": "semver"}, {"version": "5.4.106", "lessThan": "5.5", "status": "affected", "versionType": "semver"}, {"version": "5.10.24", "lessThan": "5.11", "status": "affected", "versionType": "semver"}, {"version": "5.11.7", "lessThan": "5.12", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/tap.c"], "versions": [{"version": "5.12", "status": "affected"}, {"version": "0", "lessThan": "5.12", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.105", "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": "5.12", "versionEndExcluding": "6.1.191"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.6.160"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.12.105"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.12", "versionEndExcluding": "7.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.226"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.181"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4.106"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10.24"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11.7"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/1d022885f3e6e0e238815391a4afaf3a4fb0a442"}, {"url": "https://git.kernel.org/stable/c/61dd022c55c7307ec119e5672cb141cccbecf3b1"}, {"url": "https://git.kernel.org/stable/c/15583b07fd691a844fbf7b3ad612cdc9e9a657c0"}, {"url": "https://git.kernel.org/stable/c/8b444b126cd8e4473e652f529753ed4dd1360a9c"}, {"url": "https://git.kernel.org/stable/c/164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b"}, {"url": "https://git.kernel.org/stable/c/3874892dd27d5387aa9a06f58d9060f18f351d24"}], "title": "net: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74684", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:29.752202Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:16:09.048Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74684", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-10-16T19:14:29.752202Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:14:30.354Z"}}], "cna": {"title": "net: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 7.1, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"}, "scenarios": [{"lang": "en", "value": "AV:L - A malicious KVM guest reaches tap_get_user_xdp() by kicking the virtio-net TX virtqueue; vhost_net handle_tx_copy batches XDP buffers and invokes tap_sendmsg(TUN_MSG_PTR), not via any host network packet-receive path.\nAC:L - On typical QEMU/KVM vhost-net+tap/macvtap backends with TX batching enabled, a guest fully controls virtio-net GSO headers and Ethernet frames; sending GSO with ethertype 0 deterministically hits dev_parse_header_protocol() with skb->dev NULL without races.\nPR:N - No host root or capabilities are required; a malicious cloud VM tenant only needs code execution inside a guest using virtio-net with a vhost-net tap backend, matching other guest-to-host virtio/KVM CNA scores.\nUI:N - No separate victim action is needed; the attacker submits crafted virtio-net TX descriptors from their own guest workload during normal VM operation without requiring host administrator interaction.\nS:C - Guest-supplied virtio-net TX data triggers a NULL pointer dereference in host tap_get_user_xdp(), panicking the physical host kernel and crossing the KVM guest-to-host virtualization security boundary.\nC:N - The failure mode is a NULL pointer dereference at dev->header_ops with skb->dev unset; there is no demonstrated out-of-bounds read, use-after-free, or other memory corruption that could disclose host kernel data.\nI:N - No guest-controlled host memory write or control-flow hijack occurs; the host kernel oopses on the NULL dereference before any exploitable modification beyond the immediate crash.\nA:H - The NULL pointer dereference in dev_parse_header_protocol() provokes a host kernel oops/panic in the vhost worker during guest virtio-net TX, denying availability of the hypervisor and all co-resident VMs."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "1d022885f3e6e0e238815391a4afaf3a4fb0a442", "versionType": "git"}, {"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "61dd022c55c7307ec119e5672cb141cccbecf3b1", "versionType": "git"}, {"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "15583b07fd691a844fbf7b3ad612cdc9e9a657c0", "versionType": "git"}, {"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "8b444b126cd8e4473e652f529753ed4dd1360a9c", "versionType": "git"}, {"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b", "versionType": "git"}, {"status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "lessThan": "3874892dd27d5387aa9a06f58d9060f18f351d24", "versionType": "git"}, {"status": "affected", "version": "ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d", "versionType": "git"}, {"status": "affected", "version": "54ef8243c3c8e90f1ea5792e6752e021a25c8eb3", "versionType": "git"}, {"status": "affected", "version": "ca278267d6cd9544645731732455b6b20cb0e895", "versionType": "git"}, {"status": "affected", "version": "faa3baa2828c5e1c4374f3e60041f75c64f5fcb6", "versionType": "git"}, {"status": "affected", "version": "99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748", "versionType": "git"}, {"status": "affected", "version": "4.14.226", "lessThan": "4.15", "versionType": "semver"}, {"status": "affected", "version": "4.19.181", "lessThan": "4.20", "versionType": "semver"}, {"status": "affected", "version": "5.4.106", "lessThan": "5.5", "versionType": "semver"}, {"status": "affected", "version": "5.10.24", "lessThan": "5.11", "versionType": "semver"}, {"status": "affected", "version": "5.11.7", "lessThan": "5.12", "versionType": "semver"}], "programFiles": ["drivers/net/tap.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"status": "unaffected", "version": "0", "lessThan": "5.12", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.191", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.160", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.105", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.45", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.9", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/net/tap.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/1d022885f3e6e0e238815391a4afaf3a4fb0a442"}, {"url": "https://git.kernel.org/stable/c/61dd022c55c7307ec119e5672cb141cccbecf3b1"}, {"url": "https://git.kernel.org/stable/c/15583b07fd691a844fbf7b3ad612cdc9e9a657c0"}, {"url": "https://git.kernel.org/stable/c/8b444b126cd8e4473e652f529753ed4dd1360a9c"}, {"url": "https://git.kernel.org/stable/c/164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b"}, {"url": "https://git.kernel.org/stable/c/3874892dd27d5387aa9a06f58d9060f18f351d24"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()\n\nThe commit 4f61f133f354 (\"net: tap: NULL pointer derefence in\ndev_parse_header_protocol when skb->dev is null\") fixed a crash in\ntap_get_user() by assigning skb->dev before calling tun_vnet_hdr_to_skb().\nThis is required because virtio_net_hdr_to_skb() may invoke\ndev_parse_header_protocol(), which dereferences skb->dev. Without the\nassignment, a NULL pointer dereference can occur.\n\nHowever, tap_get_user_xdp() still parses the virtio-net header before\nassigning skb->dev. When the vhost TX path passes an XDP buffer containing\na GSO virtio-net header but the protocol is set to zero on purpose,\ntun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb->dev\nis still NULL, resulting in a crash.\n\nFix this by looking up the tap device and assigning skb->dev before calling\ntun_vnet_hdr_to_skb(), matching the ordering already used in\ntap_get_user(). Preserve the existing RCU read-side critical section across\ndev_queue_xmit()."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.191", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.160", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.105", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.45", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.9", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.12"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "4.14.226"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "4.19.181"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "5.4.106"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "5.10.24"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionStartIncluding": "5.11.7"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-30T12:30:16.355Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74684", "state": "PUBLISHED", "dateUpdated": "2026-10-30T12:30:16.355Z", "dateReserved": "2026-08-15T05:44:03.926Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-22T15:32:50.846Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/tap.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "1d022885f3e6e0e238815391a4afaf3a4fb0a442", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"lessThan": "61dd022c55c7307ec119e5672cb141cccbecf3b1", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"lessThan": "15583b07fd691a844fbf7b3ad612cdc9e9a657c0", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"lessThan": "8b444b126cd8e4473e652f529753ed4dd1360a9c", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"lessThan": "164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"lessThan": "3874892dd27d5387aa9a06f58d9060f18f351d24", "status": "affected", "version": "924a9bc362a5223cd448ca08c3dde21235adc310", "versionType": "git"}, {"status": "affected", "version": "ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d", "versionType": "git"}, {"status": "affected", "version": "54ef8243c3c8e90f1ea5792e6752e021a25c8eb3", "versionType": "git"}, {"status": "affected", "version": "ca278267d6cd9544645731732455b6b20cb0e895", "versionType": "git"}, {"status": "affected", "version": "faa3baa2828c5e1c4374f3e60041f75c64f5fcb6", "versionType": "git"}, {"status": "affected", "version": "99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748", "versionType": "git"}, {"lessThan": "4.15", "status": "affected", "version": "4.14.226", "versionType": "semver"}, {"lessThan": "4.20", "status": "affected", "version": "4.19.181", "versionType": "semver"}, {"lessThan": "5.5", "status": "affected", "version": "5.4.106", "versionType": "semver"}, {"lessThan": "5.11", "status": "affected", "version": "5.10.24", "versionType": "semver"}, {"lessThan": "5.12", "status": "affected", "version": "5.11.7", "versionType": "semver"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/tap.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.12"}, {"lessThan": "5.12", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.191", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.160", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.105", "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: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()\n\nThe commit 4f61f133f354 (\"net: tap: NULL pointer derefence in\ndev_parse_header_protocol when skb->dev is null\") fixed a crash in\ntap_get_user() by assigning skb->dev before calling tun_vnet_hdr_to_skb().\nThis is required because virtio_net_hdr_to_skb() may invoke\ndev_parse_header_protocol(), which dereferences skb->dev. Without the\nassignment, a NULL pointer dereference can occur.\n\nHowever, tap_get_user_xdp() still parses the virtio-net header before\nassigning skb->dev. When the vhost TX path passes an XDP buffer containing\na GSO virtio-net header but the protocol is set to zero on purpose,\ntun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb->dev\nis still NULL, resulting in a crash.\n\nFix this by looking up the tap device and assigning skb->dev before calling\ntun_vnet_hdr_to_skb(), matching the ordering already used in\ntap_get_user(). Preserve the existing RCU read-side critical section across\ndev_queue_xmit()."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnet: tap: establecer skb -> dev antes de analizar el encabezado virtio net en tap_get_user_xdp()\n\nEl commit 4f61f133f354 ('net: tap: desreferencia de puntero NULL en dev_parse_header_protocol cuando skb -> dev es nulo') corrigi\u00f3 un fallo en tap_get_user() asignando skb -> dev antes de llamar a tun_vnet_hdr_to_skb(). Esto es necesario porque virtio_net_hdr_to_skb() puede invocar a dev_parse_header_protocol(), que desreferencia skb -> dev. Sin la asignaci\u00f3n, puede ocurrir una desreferencia de puntero NULL.\n\nSin embargo, tap_get_user_xdp() todav\u00eda analiza el encabezado virtio-net antes de asignar skb -> dev. Cuando la ruta TX de vhost pasa un b\u00fafer XDP que contiene un encabezado virtio-net GSO pero el protocolo se establece a cero a prop\u00f3sito, tun_vnet_hdr_to_skb() puede alcanzar dev_parse_header_protocol() mientras skb -> dev todav\u00eda es NULL, lo que resulta en un fallo.\n\nSolucionar esto buscando el dispositivo tap y asignando skb -> dev antes de llamar a tun_vnet_hdr_to_skb(), igualando el orden ya utilizado en tap_get_user(). Preservar la secci\u00f3n cr\u00edtica de lectura RCU existente a trav\u00e9s de dev_queue_xmit()."}], "id": "CVE-2026-74684", "lastModified": "2026-10-30T13:20:03.600", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 2.5, "impactScore": 4.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74684", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:14:29.752202Z", "version": "2.0.3"}}]}, "published": "2026-08-22T16:16:42.757", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/15583b07fd691a844fbf7b3ad612cdc9e9a657c0"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1d022885f3e6e0e238815391a4afaf3a4fb0a442"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3874892dd27d5387aa9a06f58d9060f18f351d24"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/61dd022c55c7307ec119e5672cb141cccbecf3b1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8b444b126cd8e4473e652f529753ed4dd1360a9c"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: net: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()", "id": "2521432", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521432"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nnet: tap: set skb->dev before parsing virtio net header in tap_get_user_xdp()\nThe commit 4f61f133f354 (\"net: tap: NULL pointer derefence in\ndev_parse_header_protocol when skb->dev is null\") fixed a crash in\ntap_get_user() by assigning skb->dev before calling tun_vnet_hdr_to_skb().\nThis is required because virtio_net_hdr_to_skb() may invoke\ndev_parse_header_protocol(), which dereferences skb->dev. Without the\nassignment, a NULL pointer dereference can occur.\nHowever, tap_get_user_xdp() still parses the virtio-net header before\nassigning skb->dev. When the vhost TX path passes an XDP buffer containing\na GSO virtio-net header but the protocol is set to zero on purpose,\ntun_vnet_hdr_to_skb() can reach dev_parse_header_protocol() while skb->dev\nis still NULL, resulting in a crash.\nFix this by looking up the tap device and assigning skb->dev before calling\ntun_vnet_hdr_to_skb(), matching the ordering already used in\ntap_get_user(). Preserve the existing RCU read-side critical section across\ndev_queue_xmit().", "A flaw was found in the Linux kernel's `net: tap` module. A NULL pointer dereference can occur in the `tap_get_user_xdp()` function when processing an XDP buffer with a GSO virtio-net header and a zero protocol. This can be triggered by a malicious guest in a virtualized environment, leading to a system crash and a Denial of Service (DoS)."], "name": "CVE-2026-74684", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "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": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "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-2026-74684\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74684\nhttps://lore.kernel.org/linux-cve-announce/2026082232-CVE-2026-74684-9a3c@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[924a9bc362a5223cd448ca08c3dde21235adc310,8b444b126cd8e4473e652f529753ed4dd1360a9c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[924a9bc362a5223cd448ca08c3dde21235adc310,164c31ee252ebd1ac8f44c2dfc5486b6d9a0379b)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[924a9bc362a5223cd448ca08c3dde21235adc310,3874892dd27d5387aa9a06f58d9060f18f351d24)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "ea3fb2ce5fa794d02135f5c079e05cd6fc3f545d"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "54ef8243c3c8e90f1ea5792e6752e021a25c8eb3"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "ca278267d6cd9544645731732455b6b20cb0e895"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "faa3baa2828c5e1c4374f3e60041f75c64f5fcb6"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "99b1d3f74b9ef72c2f74c8e4c078e1bc0706e748"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.14.226,4.15)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[4.19.181,4.20)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.4.106,5.5)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.10.24,5.11)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[5.11.7,5.12)"}}], "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": "semver", "value": "5.12"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,5.12)"}}, {"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": "2026-08-22T17:30:02.931846+00:00", "updated": "2026-08-25T14:00:17.975157+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}