CVE-2026-56391

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.

CVSS v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 4.2

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://cert.pl/en/posts/2026/07/CVE-2026-56391	Third Party Advisory
https://git.savannah.gnu.org/cgit/coreutils.git/	Product
https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=d64e35a8a4c0e4608321433e0d84d917e4e36371	Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:gnu:coreutils:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-07-24 09:16

Updated : 2026-08-26 13:52

NVD link : CVE-2026-56391

Mitre link : CVE-2026-56391

CVE.ORG link : CVE-2026-56391

JSON object : View

Products Affected

gnu

coreutils

CWE

CWE-125

Out-of-bounds Read

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