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.
History

Fri, 24 Jul 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 24 Jul 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu coreutils
Vendors & Products Gnu
Gnu coreutils

Fri, 24 Jul 2026 08:15:00 +0000

Type Values Removed Values Added
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.
Title Out‑of‑bounds Read in GNU coreutils
Weaknesses CWE-125
References
Metrics cvssV4_0

{'score': 4.6, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-07-24T12:31:34.245Z

Reserved: 2026-06-21T11:40:32.790Z

Link: CVE-2026-56391

cve-icon Vulnrichment

Updated: 2026-07-24T12:31:22.474Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-24T09:30:08Z