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

Attack Vector Local

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
GNU gzip unaffected
Version Status Constraints
0 affected ≤ 1.14

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Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://cert.pl/en/posts/2026/04/CVE-2026-41991/ cve-icon
https://cgit.git.savannah.gnu.org/cgit/gzip.git/commit/?id=4e6f8b24ab823146ab8776f0b7fe486ab34d4269 cve-icon
https://www.gnu.org/software/gzip/ cve-icon
History

Mon, 29 Jun 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 29 Jun 2026 12:00:00 +0000

Type Values Removed Values Added
Description 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
Title Predictable Temporary File in GNU gzip
Weaknesses CWE-377
References
Metrics cvssV4_0

{'score': 2, 'vector': 'CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CERT-PL

Published:

Updated: 2026-06-29T13:31:46.581Z

Reserved: 2026-04-23T08:06:09.511Z

Link: CVE-2026-41991

cve-icon Vulnrichment

Updated: 2026-06-29T13:31:40.967Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-29T14:00:05Z

Weaknesses