CyberSecBulletin
CVE-2026-31413NVD status: Analyzed

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-31413 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 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 342aa1ee995ef5bbf876096dc3a5e51218d76fa4, 58bd87d0e69204dbd739e4387a1edb0c4b1644e7, d13281ae7ea8902b21d99d10a2c8caf0bdec0455 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 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 342aa1ee995ef5bbf876096dc3a5e51218d76fa4 or 58bd87d0e69204dbd739e4387a1edb0c4b1644e7 or d13281ae7ea8902b21d99d10a2c8caf0bdec0455 or c845894ebd6fb43226b3118d6b017942550910c5, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12.80 or 6.18.21 or 6.19.11, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxdea9989a3f3961faede93752cd81eb5a9514d911 up to, but not including, 342aa1ee995ef5bbf876096dc3a5e51218d76fa4; 4c122e8ae14950cf6b59d208fc5160f7c601e746 up to, but not including, 58bd87d0e69204dbd739e4387a1edb0c4b1644e7; e52567173ba86dbffb990595fbe60e2e83899372 up to, but not including, d13281ae7ea8902b21d99d10a2c8caf0bdec0455; bffacdb80b93b7b5e96b26fad64cc490a6c7d6c7 up to, but not including, c845894ebd6fb43226b3118d6b017942550910c5; 6.12.75 up to, but not including, 6.12.80; 6.18.16 up to, but not including, 6.18.21; 6.19.6 up to, but not including, 6.19.11342aa1ee995ef5bbf876096dc3a5e51218d76fa4, 58bd87d0e69204dbd739e4387a1edb0c4b1644e7, d13281ae7ea8902b21d99d10a2c8caf0bdec0455, c845894ebd6fb43226b3118d6b017942550910c5, 6.12.80, 6.18.21
LinuxLinux Kernel6.12.75 up to, but not including, 6.12.80; 6.18.16 up to, but not including, 6.18.21; 6.19.6 up to, but not including, 6.19.116.12.80, 6.18.21, 6.19.11

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
HighData or code can be modified at will.
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:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR maybe_fork_scalars() is called for both BPF_AND and BPF_OR when the source operand is a constant. When dst has signed range [-1, 0], it forks the verifier state: the pushed path gets dst = 0, the current path gets dst = -1. For BPF_AND this is correct: 0 & K == 0. For BPF_OR this is wrong: 0 | K == K, not 0. The pushed path therefore tracks dst as 0 when the runtime value is K, producing an exploitable verifier/runtime divergence that allows out-of-bounds map access. Fix this by passing env->insn_idx (instead of env->insn_idx + 1) to push_stack(), so the pushed path re-executes the ALU instruction with dst = 0 and naturally computes the correct result for any opcode.

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.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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