CVE-2026-31413

High

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.

Package Linux Kernel
Published 2026-04-12
Last modified 2026-05-20
CVSS version 3.1
Patch available
Not yet patched

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-125

CVE-2026-31413 is a Out-of-bounds Read vulnerability

What is Out-of-bounds Read?

The product reads data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.12.75, 6.18.16, 6.19.6 and later are affected. No fixed version recorded yet.

Affected from
≥ 6.12.75 ≥ 6.18.16 ≥ 6.19.6

References

The following references provide additional information about CVE-2026-31413 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2026-31413?

    CVE-2026-31413 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Read flaw (CWE-125) . It affects Linux kernel versions from 6.12.75 onward . CVE-2026-31413 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-31413?

    CVE-2026-31413 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-31413?

    No patch is currently available for CVE-2026-31413. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

  • Is CVE-2026-31413 actively exploited?

    No — CVE-2026-31413 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Out-of-bounds Read (CWE-125)?

    The product reads data past the end or before the beginning of the intended buffer. View CWE-125 on MITRE CWE →