cve-2026-31495
MEDIUM CVSS 5.5 nvd
Description
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.
Timeline
- Published
- 2026-04-22
- Last Modified
- 2026-11-05
CVSS Details
- Attack Vector
- LOCAL
- Attack Complexity
- LOW
- Privileges Required
- LOW
Affected Products
- linux linux_kernel
CVSS metrics
| Version | Base | Severity | Vector | Exploitability | Impact | Source |
|---|---|---|---|---|---|---|
| 3.1 | 5.5 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
1.8 | 3.6 | nvd@nist.gov |
CPE configurations
OR
| CPE | Version range | Vulnerable |
|---|---|---|
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 2.6.22.1, < 5.10.253 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 5.11, < 5.15.203 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 5.16, < 6.1.168 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.2, < 6.6.131 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.7, < 6.12.80 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.13, < 6.18.21 | yes |
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
>= 6.19, < 6.19.11 | yes |
cpe:2.3:o:linux:linux_kernel:2.6.22:-:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* |
— | yes |
cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* |
— | yes |
NVD metadata
- NVD status
- Modified
- Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2ef71307c86a9f866d6e28f1a0c06e2e9d794474 Patch
- https://git.kernel.org/stable/c/435b576cd2faa75154777868f8cbb73bf71644d3 Patch
- https://git.kernel.org/stable/c/45c33e79ae705b7af97e3117672b6cd258dd0b1b Patch
- https://git.kernel.org/stable/c/4f7d25f3f0786402ba48ff7d13b6241d77d975f5 Patch
- https://git.kernel.org/stable/c/675c913b940488a84effdeeac5a1cfb657b59804 Patch
- https://git.kernel.org/stable/c/8f15b5071b4548b0aafc03b366eb45c9c6566704 Patch
- https://git.kernel.org/stable/c/c6cb41eaae875501eaaa487b8db6539feb092292 Patch
- https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6 Patch
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html
Linked Vulnerabilities
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"dateUpdated": "2026-11-05T22:18:34.970",
"description": "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 > TCP_CONNTRACK_SYN_SENT2 at\n policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > 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.",
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"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 > TCP_CONNTRACK_SYN_SENT2 at\n policy level, removing the manual >= TCP_CONNTRACK_MAX check.\n- CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > 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."
}
],
"id": "CVE-2026-31495",
"lastModified": "2026-11-05T22:18:34.970",
"metrics": {
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"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
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"role": "CISA Coordinator",
"timestamp": "2026-11-05T21:35:22.554497Z",
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"url": "https://git.kernel.org/stable/c/fcec5ce2d73a41668b24e3f18c803541602a59f6"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
},
{
"source": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-457936.html"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Modified",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"severity": "MEDIUM",
"source": "nvd",
"title": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ctnetlink: use netlink policy range c..."
}