CVE-2026-56289 | GNU patch is vulnerable to a denial of service (DoS) due to … | CVSS 4.6 MEDIUM

Description

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

Metadata

CVE ID: CVE-2026-56289
State: PUBLISHED
Assigner: CERT-PL
Reserved: 2026-06-20 10:58 UTC
Published: 2026-07-09 09:29 UTC
Last updated: 2026-07-09 12:21 UTC
Primary CWE: CWE-835
CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop…
Vendor / Product: GNU / patch
Sources: cve.org · NVD

Severity & Metrics

4.6 MEDIUM CVSS 4.0

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
GNU	patch	—	0 ≤ 2.8.0

Weakness (CWE)

CWE	Source	Description
CWE-835	cna	CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')

CVSS scores (1)

Score	Severity	Version	Source	Vector
4.6	MEDIUM	4.0	cna	CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L

References (3)