Medium severity · published Jul 9, 2026
CVE-2026-56288
NULL Pointer Dereference in GNU patch
5.5
CVSS
0.1%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.1% · higher than 2% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PA
patch · GNU
through 2.8.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56288
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56288
Third Party Advisory
https://cert.pl/en/posts/2026/07/CVE-2026-56288
Patch
https://cgit.git.savannah.gnu.org/cgit/patch.git/
Patch
https://cgit.git.savannah.gnu.org/cgit/patch.git/commit/?id=e6d6a4e021660679d7fc9150f981d4920f722313
More from patch
7.8
CVE-2018-20969
do_ed_script in pch.c in GNU patch through 2.7.6 does not block strings beginning with a ! character
7.8
CVE-2019-13638
GNU patch through 2.7.6 is vulnerable to OS shell command injection that can be exploited by opening a crafted patch file that contains an ed style diff payload with shell…
7.8
CVE-2018-1000156
GNU Patch version 2.7.6 contains an input validation vulnerability when processing patch files, specifically the EDITOR_PROGRAM invocation (using ed) can result in code execution
7.5
CVE-2015-1396
A Directory Traversal vulnerability exists in the GNU patch before 2.7.4
7.5
CVE-2018-6952
A double free exists in the another_hunk function in pch.c in GNU patch through 2.7.6