CVE-2026-56289: 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 pa

unknownCVE-2026-56289

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

Details

Source: NVD Recent CVEs (US · database · site)
Severity: unknown
Published: 2026-07-09
Last updated: 2026-07-09
Exploitation: Not in CISA KEV at last sync

Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-56289

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-562890.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-56289	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

low[NEW] [low] patch: Multiple vulnerabilities allow denial of servicecert-bund
unknownCVE-2026-56289: Loop with Unreachable Exit Condition in GNU patchmsrc

Recent advisories for GNU patch is

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

unknownCVE-2026-56288: GNU patch is vulnerable to a NULL pointer dereference when processing a specially crafted unif…nvd · 2026-07-09
unknownCVE-2026-56288: NULL Pointer Dereference in GNU patchmsrc · 2026-07-02
unknownCVE-2026-56289: Loop with Unreachable Exit Condition in GNU patchmsrc · 2026-07-02