CVE-2026-64132

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64132", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.036Z", "datePublished": "2026-07-19T15:40:27.590Z", "dateUpdated": "2026-08-05T12:39:34.060Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:39:34.060Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: refresh hdr pointer before ioam6_event()\n\nReported by Sashiko:\n\nIn ipv6_hop_ioam(), the hdr pointer is initialized to point into the\nskb's linear data buffer. Later, the code calls skb_ensure_writable(),\nwhich might reallocate the buffer:\n\n\tif (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))\n\t\tgoto drop;\n\n\t/* Trace pointer may have changed */\n\ttrace = (struct ioam6_trace_hdr *)(skb_network_header(skb)\n\t\t\t\t\t + optoff + sizeof(*hdr));\n\n\tioam6_fill_trace_data(skb, ns, trace, true);\n\n\tioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),\n\t\t GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);\n\nIf the skb is cloned or lacks sufficient linear headroom,\nskb_ensure_writable() will invoke pskb_expand_head(), which reallocates\nthe skb's data buffer and frees the old one, invalidating pointers to\nit. While the code recalculates the trace pointer immediately after the\ncall to skb_ensure_writable(), it fails to recalculate the hdr pointer.\n\nThis patch fixes the above by recalculating the hdr pointer before\npassing hdr->opt_len to ioam6_event(), so that we avoid any UaF."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - The bug is in `ipv6_hop_ioam()`, reached from `ipv6_rcv()` \u2192 `ip6_rcv_core()` \u2192 `ipv6_parse_hopopts()` \u2192 `ip6_parse_tlv()` when processing IPv6 hop-by-hop IOAM options on ingress. A remote attacker can deliver the trigger with a crafted IPv6 packet to any internet-facing or LAN-reachable host/router that has IOAM ingress enabled.\nAC:L - Exploitation requires `skb_ensure_writable()` to reallocate via `pskb_expand_head()`, which occurs when the skb is cloned (e.g., bridge flooding/multicast forwarding sets `skb->cloned` on the original before local delivery to the IP stack). An attacker can reliably create this condition with concurrent traffic/topology choices rather than depending on uncontrollable timing or memory layout.\nPR:N - The attacker needs no privileges on the victim system\u2014only the ability to send IPv6 packets. IOAM namespace/sysctl configuration is a victim-side deployment prerequisite (typical on carrier/ISP telemetry nodes), not a privilege the attacker must hold.\nUI:N - Exploitation is fully attacker-driven by sending a malicious IPv6 packet and requires no action from a victim user.\nS:U - The vulnerability is a kernel heap use-after-free in IPv6 packet processing; successful exploitation would compromise the kernel/host itself, not cross a separate security authority such as a VM guest-to-host or sandbox boundary.\nC:H - After `pskb_expand_head()` frees the old skb buffer, the stale `hdr` pointer is dereferenced for `hdr->opt_len`, constituting a use-after-free read of freed kernel memory; that attacker-influenced length is then used in `ioam6_event_put_trace()`/`nla_put()`, enabling out-of-bounds kernel memory reads and information disclosure.\nI:H - Use-after-free of heap metadata enables memory corruption primitives; the corrupted `opt_len` fed into netlink attribute construction can cause out-of-bounds reads whose contents are attacker-influenced, and UAF bugs in skb handling are classically leveragable toward arbitrary kernel write/code execution.\nA:H - Reading freed memory and passing a corrupted length into `nla_put()` can cause kernel oops/panic (especially with KASAN/overflow checks), and UAF conditions inherently risk system crashes even when full exploitation is not attempted."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/ipv6/exthdrs.c"], "versions": [{"version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "lessThan": "769723124b7c3b2bfea4cf68ad292698b87c8d01", "status": "affected", "versionType": "git"}, {"version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "lessThan": "24de676da63c1122d2c13b0d546238b66d1b4e62", "status": "affected", "versionType": "git"}, {"version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "lessThan": "5af905aa8e91ff8d94572a1e089558f21dcf24ed", "status": "affected", "versionType": "git"}, {"version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "lessThan": "e46e6bc97fb1f339730ff1ba74267fbf48e7a422", "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/ipv6/exthdrs.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.92", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.34", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.11", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1", "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": "6.9", "versionEndExcluding": "6.12.92"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.0.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/769723124b7c3b2bfea4cf68ad292698b87c8d01"}, {"url": "https://git.kernel.org/stable/c/24de676da63c1122d2c13b0d546238b66d1b4e62"}, {"url": "https://git.kernel.org/stable/c/5af905aa8e91ff8d94572a1e089558f21dcf24ed"}, {"url": "https://git.kernel.org/stable/c/e46e6bc97fb1f339730ff1ba74267fbf48e7a422"}], "title": "ipv6: ioam: refresh hdr pointer before ioam6_event()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["net/ipv6/exthdrs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "769723124b7c3b2bfea4cf68ad292698b87c8d01", "status": "affected", "version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "versionType": "git"}, {"lessThan": "24de676da63c1122d2c13b0d546238b66d1b4e62", "status": "affected", "version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "versionType": "git"}, {"lessThan": "5af905aa8e91ff8d94572a1e089558f21dcf24ed", "status": "affected", "version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "versionType": "git"}, {"lessThan": "e46e6bc97fb1f339730ff1ba74267fbf48e7a422", "status": "affected", "version": "f655c78d6225f585ef60a9d93ffb79d507ff3ad3", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["net/ipv6/exthdrs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.92", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.34", "versionType": "semver"}, {"lessThanOrEqual": "7.0.*", "status": "unaffected", "version": "7.0.11", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.1", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "8DA2A75E-CE43-4FDB-A0D5-74277B51F5B2", "versionEndExcluding": "6.12.92", "versionStartIncluding": "6.9", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "A4B1EF6D-18D7-4838-BC37-7499D5DCC3C0", "versionEndExcluding": "6.18.34", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "0520D091-FC52-4A50-AF07-70AE7D08B750", "versionEndExcluding": "7.0.11", "versionStartIncluding": "6.19", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*", "matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*", "matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*", "matchCriteriaId": "EC732D08-5F7B-46D9-B154-E60C7F4F0A97", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*", "matchCriteriaId": "E5910A9D-F60A-409A-B486-FE66BFEBA9B9", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: refresh hdr pointer before ioam6_event()\n\nReported by Sashiko:\n\nIn ipv6_hop_ioam(), the hdr pointer is initialized to point into the\nskb's linear data buffer. Later, the code calls skb_ensure_writable(),\nwhich might reallocate the buffer:\n\n\tif (skb_ensure_writable(skb, optoff + 2 + hdr->opt_len))\n\t\tgoto drop;\n\n\t/* Trace pointer may have changed */\n\ttrace = (struct ioam6_trace_hdr *)(skb_network_header(skb)\n\t\t\t\t\t + optoff + sizeof(*hdr));\n\n\tioam6_fill_trace_data(skb, ns, trace, true);\n\n\tioam6_event(IOAM6_EVENT_TRACE, dev_net(skb->dev),\n\t\t GFP_ATOMIC, (void *)trace, hdr->opt_len - 2);\n\nIf the skb is cloned or lacks sufficient linear headroom,\nskb_ensure_writable() will invoke pskb_expand_head(), which reallocates\nthe skb's data buffer and frees the old one, invalidating pointers to\nit. While the code recalculates the trace pointer immediately after the\ncall to skb_ensure_writable(), it fails to recalculate the hdr pointer.\n\nThis patch fixes the above by recalculating the hdr pointer before\npassing hdr->opt_len to ioam6_event(), so that we avoid any UaF."}], "id": "CVE-2026-64132", "lastModified": "2026-08-13T15:10:12.260", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-07-19T16:17:55.000", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/24de676da63c1122d2c13b0d546238b66d1b4e62"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/5af905aa8e91ff8d94572a1e089558f21dcf24ed"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/769723124b7c3b2bfea4cf68ad292698b87c8d01"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/e46e6bc97fb1f339730ff1ba74267fbf48e7a422"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: ipv6: ioam: refresh hdr pointer before ioam6_event()", "id": "2502619", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502619"}, "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-825", "details": ["A flaw was found in the Linux kernel's IPv6 In-situ Operations, Administration, and Maintenance (IOAM) component. This vulnerability, a use-after-free, occurs when the kernel fails to correctly update a pointer after reallocating a network packet's buffer. This oversight could allow an attacker to trigger a system crash, leading to a denial of service, or potentially lead to more severe impacts like information disclosure or arbitrary code execution."], "name": "CVE-2026-64132", "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": "Under investigation", "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": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "impact": "important", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-64132\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-64132\nhttps://lore.kernel.org/linux-cve-announce/2026071927-CVE-2026-64132-dd76@gregkh/T"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f655c78d6225f585ef60a9d93ffb79d507ff3ad3,769723124b7c3b2bfea4cf68ad292698b87c8d01)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f655c78d6225f585ef60a9d93ffb79d507ff3ad3,24de676da63c1122d2c13b0d546238b66d1b4e62)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f655c78d6225f585ef60a9d93ffb79d507ff3ad3,5af905aa8e91ff8d94572a1e089558f21dcf24ed)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[f655c78d6225f585ef60a9d93ffb79d507ff3ad3,e46e6bc97fb1f339730ff1ba74267fbf48e7a422)"}}], "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": "6.9"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.9)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.92,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.34,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.0.11,7.1.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.1,*]"}}], "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": "2026-07-21T10:45:02.434575+00:00", "updated": "2026-08-13T18:15:04.838606+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}