CVE-2026-56288: GNU patch is vulnerable to a NULL pointer dereference when processing a specially crafted unified-diff patch f

Q: How do I fix CVE-2026-56288?

patch: upgrade to newer than 2.8.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-56288 being exploited?

CVE-2026-56288 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-56288 affect?

CVE-2026-56288 affects patch. Severity is medium (CVSS 5.5). 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

Q: How urgent is CVE-2026-56288?

Priority 20/100. No elevated risk signals yet.

Routine

MEDIUM 5.5UPGRADE

CVE-2026-56288 is a medium-severity flaw (CVSS 5.5) affecting patch. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.1% (top 98%)
CISA exploited list	No
Weakness	CWE-476
Published	2026-07-09
Last modified	2026-10-25

Publisher (CNA): CERT.PL · Vendor: gnu

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-09 11:16 UTCPublished CVE record published
2026-10-25 17:10 UTCUpdated Record last modified

gnu patch UPGRADE

Affected: <= 2.8.0

Fixed in: newer than 2.8.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy patch || rpm -q patch || patch --version

2. UPGRADE to newer than 2.8.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade patch

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade patch

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Advisories and coverage

Official advisories

CERT Polska: Vulnerabilities in GNU patch software 2026-07-09

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-56288?

patch: upgrade to newer than 2.8.0. Exact commands for each OS are on this page.

Is CVE-2026-56288 being exploited?

CVE-2026-56288 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-56288 affect?

CVE-2026-56288 affects patch. Severity is medium (CVSS 5.5). 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

How urgent is CVE-2026-56288?

Priority 20/100. No elevated risk signals yet.

Related CVEs

CVE-2026-56289 MEDIUM 5.5 UPGRADE GNU patch is vulnerable to a denial of service (DoS) due to improper validation of hunk (single block of chang

References

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