CVE-2026-31495 (GCVE-0-2026-31495)
Vulnerability from cvelistv5
Published
2026-04-22 13:54
Modified
2026-04-22 13:54
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: use netlink policy range checks
Replace manual range and mask validations with netlink policy
annotations in ctnetlink code paths, so that the netlink core rejects
invalid values early and can generate extack errors.
- CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at
policy level, removing the manual >= TCP_CONNTRACK_MAX check.
- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE
(14). The normal TCP option parsing path already clamps to this value,
but the ctnetlink path accepted 0-255, causing undefined behavior when
used as a u32 shift count.
- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with
CTA_FILTER_F_ALL, removing the manual mask checks.
- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding
a new mask define grouping all valid expect flags.
Extracted from a broader nf-next patch by Florian Westphal, scoped to
ctnetlink for the fixes tree.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 Version: c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"include/uapi/linux/netfilter/nf_conntrack_common.h",
"net/netfilter/nf_conntrack_netlink.c",
"net/netfilter/nf_conntrack_proto_tcp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "435b576cd2faa75154777868f8cbb73bf71644d3",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "2ef71307c86a9f866d6e28f1a0c06e2e9d794474",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "4f7d25f3f0786402ba48ff7d13b6241d77d975f5",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "fcec5ce2d73a41668b24e3f18c803541602a59f6",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "675c913b940488a84effdeeac5a1cfb657b59804",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "c6cb41eaae875501eaaa487b8db6539feb092292",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "45c33e79ae705b7af97e3117672b6cd258dd0b1b",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
},
{
"lessThan": "8f15b5071b4548b0aafc03b366eb45c9c6566704",
"status": "affected",
"version": "c8e2078cfe414a99cf6f2f2f1d78c7e75392e9d4",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"include/uapi/linux/netfilter/nf_conntrack_common.h",
"net/netfilter/nf_conntrack_netlink.c",
"net/netfilter/nf_conntrack_proto_tcp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.22"
},
{
"lessThan": "2.6.22",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.253",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.203",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.168",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.131",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.80",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.21",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.253",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.203",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.168",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.131",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.80",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.21",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.19.11",
"versionStartIncluding": "2.6.22",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0",
"versionStartIncluding": "2.6.22",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range checks\n\nReplace manual range and mask validations with netlink policy\nannotations in ctnetlink code paths, so that the netlink core rejects\ninvalid values early and can generate extack errors.\n\n- CTA_PROTOINFO_TCP_STATE: reject values \u003e TCP_CONNTRACK_SYN_SENT2 at\n policy level, removing the manual \u003e= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values \u003e TCP_MAX_WSCALE\n (14). The normal TCP option parsing path already clamps to this value,\n but the ctnetlink path accepted 0-255, causing undefined behavior when\n used as a u32 shift count.\n- CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with\n CTA_FILTER_F_ALL, removing the manual mask checks.\n- CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding\n a new mask define grouping all valid expect flags.\n\nExtracted from a broader nf-next patch by Florian Westphal, scoped to\nctnetlink for the fixes tree."
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T13:54:17.591Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3"
},
{
"url": "https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474"
},
{
"url": "https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5"
},
{
"url": "https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6"
},
{
"url": "https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804"
},
{
"url": "https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292"
},
{
"url": "https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b"
},
{
"url": "https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704"
}
],
"title": "netfilter: ctnetlink: use netlink policy range checks",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-31495",
"datePublished": "2026-04-22T13:54:17.591Z",
"dateReserved": "2026-03-09T15:48:24.102Z",
"dateUpdated": "2026-04-22T13:54:17.591Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…