UBUNTU-CVE-2026-56289
GNU patch versions used in various Ubuntu releases are vulnerable to a denial of service (DoS) 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 patch utility to enter an effectively infinite loop, resulting in excessive CPU consumption and unresponsiveness. This issue has been fixed in a specific commit.
AI Analysis
Technical Summary
The vulnerability in GNU patch arises from improper validation of hunk line offsets in unified-diff input, allowing an attacker to craft a patch file with an extremely large line number. When processed, this causes the patch utility to enter an effectively infinite processing loop attempting to locate the specified position, leading to denial of service through excessive CPU usage. The issue affects multiple specific versions of GNU patch distributed with Ubuntu and has been fixed in commit faba04ef4f2b410257f76c1b9dc85e350929c4b9.
Potential Impact
An attacker supplying a malicious patch file can cause the patch utility to become unresponsive due to excessive CPU consumption, effectively resulting in a denial of service. This disrupts normal operations requiring manual termination of the process. There is no indication of privilege escalation or data compromise from the provided information.
Mitigation Recommendations
A fix for this vulnerability is available and has been applied in the commit faba04ef4f2b410257f76c1b9dc85e350929c4b9. Users should update to patched versions of GNU patch as provided by their Ubuntu distribution. Since this is not a cloud service, manual patching is required. Check the Ubuntu vendor advisories for the latest patched package versions.
UBUNTU-CVE-2026-56289
Description
GNU patch versions used in various Ubuntu releases are vulnerable to a denial of service (DoS) 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 patch utility to enter an effectively infinite loop, resulting in excessive CPU consumption and unresponsiveness. This issue has been fixed in a specific commit.
CVSS v4.0
Affected software
pkg:deb/ubuntu/[email protected]+esm1?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/[email protected]?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]?arch=source&distro=bionicpkg:deb/ubuntu/[email protected]?arch=source&distro=jammypkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in GNU patch arises from improper validation of hunk line offsets in unified-diff input, allowing an attacker to craft a patch file with an extremely large line number. When processed, this causes the patch utility to enter an effectively infinite processing loop attempting to locate the specified position, leading to denial of service through excessive CPU usage. The issue affects multiple specific versions of GNU patch distributed with Ubuntu and has been fixed in commit faba04ef4f2b410257f76c1b9dc85e350929c4b9.
Potential Impact
An attacker supplying a malicious patch file can cause the patch utility to become unresponsive due to excessive CPU consumption, effectively resulting in a denial of service. This disrupts normal operations requiring manual termination of the process. There is no indication of privilege escalation or data compromise from the provided information.
Mitigation Recommendations
A fix for this vulnerability is available and has been applied in the commit faba04ef4f2b410257f76c1b9dc85e350929c4b9. Users should update to patched versions of GNU patch as provided by their Ubuntu distribution. Since this is not a cloud service, manual patching is required. Check the Ubuntu vendor advisories for the latest patched package versions.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-56289
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:16.04:LTS","Ubuntu:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a58b46f68715ace43d83ef2
Added to database: 07/16/2026, 10:37:35 UTC
Last enriched: 07/16/2026, 11:47:53 UTC
Last updated: 07/31/2026, 19:24:46 UTC
Views: 5
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