GNU patch is vulnerable to a denial of service (DoS) due to improper validation of hunk (single block of changes in
Affects patchSource GCVE Database
Not known to be exploited · CVSS 4.6 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 9 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10patchpkg:deb/ubuntu/patch?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSpatchpkg:deb/ubuntu/patch?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10patchpkg:deb/ubuntu/patch?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSpatchpkg:deb/ubuntu/patch?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSpatchpkg:deb/ubuntu/patch?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSpatchpkg:deb/ubuntu/patch?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability has been implemented in a specific commit. Users should update to the fixed version of GNU patch as indicated by their vendor or distribution. Since the vulnerability is fixed, applying the official patch or upgrading to a fixed release is the recommended mitigation.
Description
GNU patch contains a denial of service (DoS) vulnerability caused by improper validation of hunk line offsets in unified-diff input. A malicious patch file can specify an extremely large line number, causing the utility to enter an effectively infinite processing loop and consume excessive CPU resources, making the process unresponsive. This issue has been fixed in a specific commit.
References
- ubuntu.com/security/CVE-2026-56289 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-56289 (opens in a new tab)
- cert.pl/en/posts/2026/07/CVE-2026-56288 (opens in a new tab)
- cgit.git.savannah.gnu.org/cgit/patch.git/ (opens in a new tab)
- cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=faba04ef4f2b410257f76c1b9dc85e350929c4b9 (opens in a new tab)