CVE-2026-41991

GNU gzip contains a vulnerability in the gzexe utility related to insecure temporary file handling. When the mktemp utility is not available in the user’s PATH, gzexe falls back to constructing a temporary file path based solely on the process ID (PID). This predictable filename is created without exclusive access or existence checks. A local attacker can pre‑create the predicted temporary file path as a symbolic link pointing to an arbitrary file writable by the victim. When gzexe runs, it follows the symlink and overwrites the target file, resulting in a time‑of‑check to time‑of‑use (TOCTOU) condition that allows arbitrary file overwrite. This issue has been fixed in the commit 4e6f8b24ab823146ab8776f0b7fe486ab34d4269

CVSS v3 4.7 MEDIUM

4.7^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.0 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cert.pl/en/posts/2026/04/CVE-2026-41991/	Broken Link
https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269	Patch
https://www.gnu.org/software/gzip/	Product

Configurations

Configuration 1 (hide)

cpe:2.3:a:gnu:gzip:*:*:*:*:*:*:*:*

History

01 Jul 2026, 14:02

Type	Values Removed	Values Added
CPE		cpe:2.3:a:gnu:gzip::::::::
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 4.7
References	~~() https://cert.pl/en/posts/2026/04/CVE-2026-41991/ -~~	() https://cert.pl/en/posts/2026/04/CVE-2026-41991/ - Broken Link
References	~~() https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269 -~~	() https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269 - Patch
References	~~() https://www.gnu.org/software/gzip/ -~~	() https://www.gnu.org/software/gzip/ - Product
First Time		Gnu Gnu gzip

29 Jun 2026, 12:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-29 12:16

Updated : 2026-07-01 14:02

NVD link : CVE-2026-41991

Mitre link : CVE-2026-41991

CVE.ORG link : CVE-2026-41991

JSON object : View

Products Affected

gnu

gzip

CWE

CWE-377

Insecure Temporary File

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