Bug 2498462 (CVE-2026-56289)

Summary: CVE-2026-56289 patch: GNU patch: Denial of Service via crafted unified-diff input
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in GNU patch. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by supplying a specially crafted patch file. The improper validation of hunk (single block of changes in diff) line offsets in unified-diff input can lead to an effectively infinite processing loop, resulting in excessive CPU consumption and making the utility unresponsive, requiring manual termination.
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Description OSIDB Bzimport 2026-07-09 11:01:12 UTC 
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