PT-2026-56776 · Gnu · Patch

Marcin Wyczechowski + 1 · Published 2026-07-09 · Updated 2026-07-09 · CVE-2026-56289

Mitre

CVSS v4.0

4.6

Medium

Base vector

AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

GNU patch is vulnerable to a denial of service (DoS) due to improper validation of hunk (single block of changes in diff) line offsets in unified-diff input. A specially crafted patch can specify an extremely large line number, causing the application to enter an effectively infinite processing loop while attempting to locate the requested position. This results in excessive CPU consumption and prevents the process from completing. An attacker can trigger this behavior by supplying a malicious patch file, causing the utility to become unresponsive and require manual termination.

This issue has been fixed in the commit faba04ef4f2b410257f76c1b9dc85e350929c4b9

Fix

Infinite Loop

Weakness Enumeration

CWE-835

Related Identifiers

CVE-2026-56289

Affected Products

Patch

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-56289 · Security Note
• https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=faba04ef4f2b410257f76c1b9dc85e350929c4b9 · Patch
• https://cgit.git.savannah.gnu.org/cgit/patch.git · Note
• https://cert.pl/en/posts/2026/07/CVE-2026-56288 · Note