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No exploitation reportedFix available

CVE-2026-56289

No exploitation reported by the sources we read.

  • Published2026-07-09
  • WeaknessCWE-835

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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

Timeline

dates in UTC
  1. 2026-07-0911:16CVE publishedNVD

Versions per branch

NVD
Gnu patch
BranchAffectedFixed in
2.8≤ 2.8.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • patchUbuntu:Pro:14.04:LTSall versions · no fixed version listed
  • patchUbuntu:26.10all versions · no fixed version listed
  • patchUbuntu:26.04:LTSall versions · no fixed version listed
  • patchUbuntu:25.10all versions · no fixed version listed
  • patchUbuntu:24.04:LTSall versions · no fixed version listed
  • patchUbuntu:22.04:LTSall versions · no fixed version listed
  • patchUbuntu:20.04:LTSall versions · no fixed version listed
  • patchUbuntu:18.04:LTSall versions · no fixed version listed

31 more package ranges on OSV.dev

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS 4.0 vector
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-07-09
Last Modified
2026-10-25
NVD status
Analyzed
GitHub Advisory
GHSA-3m3r-f94v-4mf8

Frequently asked questions

What is 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 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

Is CVE-2026-56289 actively exploited?

Active exploitation of CVE-2026-56289 has not been confirmed. Its EPSS score was 0.1% on 2026-11-09, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-56289?

CVE-2026-56289 has a CVSS v3 base score of 5.5 (MEDIUM severity), with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

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