CVE-2026-31413
HighIn 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.
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-125CVE-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.
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.
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PatchKernel patch commithttps://git.kernel.org/stable/c/342aa1ee995ef5bbf876096dc3a5e51218d76fa4
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PatchKernel patch commithttps://git.kernel.org/stable/c/58bd87d0e69204dbd739e4387a1edb0c4b1644e7
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PatchKernel patch commithttps://git.kernel.org/stable/c/c845894ebd6fb43226b3118d6b017942550910c5
Frequently asked questions
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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.
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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.
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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.
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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 →