NULL pointer dereference in GNU Patch

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

EPSS: 0.001 (1.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-56288?
CVE-2026-56288 is a medium-severity vulnerability in GNU Patch, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2026-07-09.
How severe is CVE-2026-56288?
Medium severity. CVSS v3 base score is 5.5 out of 10.