CVE-2026-41991
Gnu Gzip ≤ 1.14
Raw 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
CVE-2026-41991 is a low-severity Insecure Temporary File (CWE-377) vulnerability in Gnu Gzip. Its CVSS base score is 2.0 (Low).
Operationally, ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-40068
- 🇵🇱 CERT-PL: cert.pl
Vulnerability Data
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…
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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
- CWE(s)
Related Threats
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
AC-3 enforces file-system access authorizations so that temporary files cannot be read or modified by unauthorized processes.
AC-6 reduces the privileges available to processes that create or access temporary files, limiting blast radius if a file is predictable or left readable.
SC-4 directly stops unauthorized information leakage through shared resources such as world-writable temporary directories.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require avoiding insecure temp-file creation patterns.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect insecure temporary files but does not prevent their creation.
Secure development life cycle mandates secure handling of temporary files during design and coding.
Application security requirements can specify secure temporary-file creation and access controls.
Secure system architecture principles discourage insecure temporary-file patterns but do not directly address them.
Secure coding standards explicitly require safe temporary-file APIs and permissions.
Information deletion policies may cover secure removal of temporary files after use.