CVE-2026-41991

Local file overwrite via predictable temporary pathname

Published Jun 29, 2026 · Updated Jun 29, 2026

Insecure temporary-file handling in GNU gzip 1.14 and earlier allows local users to overwrite victim-writable files through gzexe. When mktemp is absent from PATH, gzexe derives a temporary pathname solely from its PID, then opens it without exclusive creation or an existence check. A local user who predicts the PID-based name and plants a symbolic link can redirect the victim's write to any file writable by the victim.

CVSS severity2.0
Low
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure temporary-file handling in GNU gzip 1.14 and earlier allows local users to overwrite victim-writable files through gzexe. When mktemp is absent from PATH, gzexe derives a temporary pathname solely from its PID, then opens it without exclusive creation or an existence check. A local user who predicts the PID-based name and plants a symbolic link can redirect the victim's write to any file writable by the victim.

The record

CVE
CVE-2026-41991
Published
Jun 29, 2026
Updated
Jun 29, 2026
Vendor
The GnuPG Project
Product
gzip
Classifications
CWE-377, T1565.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 29, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The GnuPG Project · gzipversion=0 <=1.14

Published CVSS scores

2.0CERT.PLCVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-377Insecure Temporary File
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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