CVE-2026-56288

GNU patch is vulnerable to a NULL pointer dereference when processing a specially crafted unified-diff patch file. Improper handling of consecutive end-of-file newline markers can corrupt internal hunk (single block of changes in diff) data structures, causing the application to pass a NULL pointer to fwrite() during patch processing. An attacker can trigger this condition with a malicious patch file, causing the utility to crash and resulting in a denial of service. This issue has been fixed in the commit e6d6a4e021660679d7fc9150f981d4920f722313

CVSS 4.0

4.6CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS 3.1

5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.1% chance of exploitation in the next 30 days; higher than 1% of CVEs (scores of 2026-10-25)

CWE

CWE-476

Published

2026-07-09

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• gnu:patch

References

• https://cert.pl/en/posts/2026/07/CVE-2026-56288
• https://cgit.git.savannah.gnu.org/cgit/patch.git/
• https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=e6d6a4e021660679d7fc9150f981d4920f722313

Check your stackJSON