CVE-2026-56391

MediumCVSS 6.1/10Last modified Oct 24, 2026

Description

GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters by repeatedly processing a fixed pointer instead of advancing through the input, resulting in an inflated length value. This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input.

When running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure.

This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.

Metrics

CVSS 3.1 6.1/10CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

Weakness enumeration

Affected software

No affected versions have been published.

Timeline

Published
Jul 24, 2026
Last modified
Oct 24, 2026
NVD status
Analyzed

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CVE-2026-56391: Medium severity, CVSS 6.1 | Vulnix