Executive brief
A vulnerability exists in the 'uniq' utility of GNU coreutils, a fundamental set of tools used in Linux and Unix-like operating systems. When processing specially crafted text files using certain character-checking options, the tool may crash or inadvertently expose small amounts of system memory. This could lead to a service disruption or the leakage of sensitive information to a local user.
Technical details
An out-of-bounds read vulnerability exists in the 'uniq' utility of GNU coreutils within the find_field() function. The flaw is caused by the incorrect handling of multibyte characters when the -w (--check-chars) flag is active; the function fails to advance a pointer correctly while calculating character byte lengths, leading to an inflated length value. This value is subsequently passed to memcmp(), resulting in a read beyond the allocated buffer. An attacker can exploit this by providing crafted multibyte input, potentially causing a denial-of-service (crash) or disclosing adjacent heap memory. The issue is fixed in commit d64e35a8a4c0e4608321433e0d84d917e4e36371.
Affected products
- GNU coreutils 9.5 through 9.11
Timeline
- 2026-07-24: disclosed
- 2026-07-24: advisory