Incorrect Calculation of Buffer Size Affecting perf6.18-debuginfo package, versions <1:6.18.25-52.107.amzn2023
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-AMZN2023-PERF618DEBUGINFO-16886071
- published27 May 2026
- disclosed12 Apr 2026
Introduced: 12 Apr 2026
CVE-2026-31413 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 perf6.18-debuginfo to version 1:6.18.25-52.107.amzn2023 or higher.
This issue was patched in ALAS2023-2026-1746.
NVD Description
Note: Versions mentioned in the description apply only to the upstream perf6.18-debuginfo package and not the perf6.18-debuginfo package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
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.
References
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-31413
- https://git.kernel.org/stable/c/342aa1ee995ef5bbf876096dc3a5e51218d76fa4
- https://git.kernel.org/stable/c/58bd87d0e69204dbd739e4387a1edb0c4b1644e7
- https://git.kernel.org/stable/c/c845894ebd6fb43226b3118d6b017942550910c5
- https://git.kernel.org/stable/c/d13281ae7ea8902b21d99d10a2c8caf0bdec0455