Linux: Out-of-bounds Read
CVE-2026-31674 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa, af9b7e2b765966457f4ec23be5bd34a141f89574, 29ea965a1353bc8303877422f79c8211e9ba9c55 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.17% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa or af9b7e2b765966457f4ec23be5bd34a141f89574 or 29ea965a1353bc8303877422f79c8211e9ba9c55 or c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.253 or 5.15.203 or 6.1.168 or 6.6.131, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, af9b7e2b765966457f4ec23be5bd34a141f89574; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 29ea965a1353bc8303877422f79c8211e9ba9c55; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, ded71f5684df16fa645cca5bf4fe6b0cd8a46119; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, d8795fde1f78669a87c87ac29fceab2f104daa8c; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, a28ebf6f99de270d6338ccdc3b49f3e818f99b7b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 9d3f027327c2fa265f7f85ead41294792c3296ed; and 1 more ranges | 13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa, af9b7e2b765966457f4ec23be5bd34a141f89574, 29ea965a1353bc8303877422f79c8211e9ba9c55, c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59, ded71f5684df16fa645cca5bf4fe6b0cd8a46119, d8795fde1f78669a87c87ac29fceab2f104daa8c |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) | V3.1.6 and later; V3.1.5 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) | V3.1.6 and later; V3.1.5 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) | V3.1.6 and later; V3.1.5 and later; V3.1.7 and later | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) | V3.1.6 and later; V3.1.5 and later; V3.1.7 and later | Not stated |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) | V3.1.6 and later; V3.1.5 and later; V3.1.7 and later | Not stated |
| Linux | Linux Kernel | 2.6.12.1 up to, but not including, 5.10.253; 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.168; 6.2 up to, but not including, 6.6.131; 6.7 up to, but not including, 6.12.80; 6.13 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 2.6.12; and 1 more ranges | 5.10.253, 5.15.203, 6.1.168, 6.6.131, 6.12.80, 6.18.21 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check() Reject rt match rules whose addrnr exceeds IP6T_RT_HOPS. rt_mt6() expects addrnr to stay within the bounds of rtinfo->addrs[]. Validate addrnr during rule installation so malformed rules are rejected before the match logic can use an out-of-range value.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa
- git.kernel.org/stable/c/29ea965a1353bc8303877422f79c8211e9ba9c55
- git.kernel.org/stable/c/9d3f027327c2fa265f7f85ead41294792c3296ed
- git.kernel.org/stable/c/a28ebf6f99de270d6338ccdc3b49f3e818f99b7b
- git.kernel.org/stable/c/af9b7e2b765966457f4ec23be5bd34a141f89574
- git.kernel.org/stable/c/c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59
- git.kernel.org/stable/c/d8795fde1f78669a87c87ac29fceab2f104daa8c
- git.kernel.org/stable/c/ded71f5684df16fa645cca5bf4fe6b0cd8a46119
Other references
Recent Out-of-bounds Read vulnerabilities
- 9.4 Critical severity
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 9.1 Critical severity
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