CVE-2026-56391

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 34/100
Published: 2026-07-24 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: Active
S: X
AT: None
VC: Low
VI: None
VA: Low

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.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
gnu coreutils 9.5 – 9.11

Bug Bounty Relevance

34 / 100
✓ No authentication
✓ Low complexity

CVSS Score

4.6 / 10.0 v4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.13%
Raw Score 0.001310
Percentile 2.7%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00131
2026-10-28
0.00131

Intelligence Sources

nvd ref →