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TI-2026-30385 Aliases CVE-2026-41991GHSA-67v8-88jf-4x6q

Predictable Temporary File in GNU gzip

Priority LOW 10CWE-377Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Passive
Attack complexity
High
Attack requirements
Present
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Partial Red Hat: 6 fixed, 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00117 1st percentileScored 2026-11-07
Fix Partial Red Hat: 7 advisoriesRed Hat: 6 fixed, 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
GNUgzipup to 1.14—No fix listedCNA
  • gzip VendorGNU Affected up to 1.14 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:gnu:gzip:*:*:*:*:*:*:*:*up to 1.14VulnerableGNU
  • cpe:2.3:a:gnu:gzip:*:*:*:*:*:*:*:* Versions up to 1.14 Vulnerable ·GNU

Remediation

Red Hat 7 advisories

  • RHSA-2026:79717 Released 2026-10-08 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images gzip-1.15-1.hum1@aarch64, gzip-1.15-1.hum1@src, gzip-1.15-1.hum1@x86_64
  • RHSA-2026:66018 Released 2026-09-09 · Red Hat rating Important
    Red Hat Update Infrastructure 5.3 security update
    • Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
  • RHSA-2026:65998 Released 2026-09-09 · Red Hat rating Moderate
    gzip security update
    • Red Hat Enterprise Linux BaseOS (v. 8) gzip-1.9-15.el8_10
Show 4 more Red Hat advisories
  • RHSA-2026:61783 Released 2026-08-31 · Red Hat rating Important
    A Subscription Management tool for finding and reporting Red Hat product usage
    • Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
  • RHSA-2026:61623 Released 2026-08-31 · Red Hat rating Moderate
    gzip security update
    • Red Hat Enterprise Linux BaseOS (v. 9) gzip-1.12-2.el9_8
  • RHSA-2026:61625 Released 2026-08-31 · Red Hat rating Moderate
    gzip security update
    • Red Hat Enterprise Linux BaseOS (v. 10) gzip-1.13-4.el10_2
  • RHSA-2026:33771 Released 2026-06-30 · Red Hat rating Moderate
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images gzip-1.14-2.2.hum1@aarch64, gzip-1.14-2.2.hum1@src, gzip-1.14-2.2.hum1@x86_64

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 7AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 4AffectedNo fix yet: Fix deferred
Red Hat OpenShift Container Platform 5AffectedNo fix yet: Fix deferred
Red Hat OpenShift Dev SpacesAffectedNo fix yet: Fix deferred
Red Hat Discovery 2Fixed RHSA-2026:61783
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:61625
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:65998
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:61623
Red Hat Hardened ImagesFixed RHSA-2026:33771, RHSA-2026:79717
Red Hat Update Infrastructure 5Fixed RHSA-2026:66018
Not affected: 1 product
  • Red Hat Discovery 2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-41991
  2. 2026-10-03 Alias added: GHSA-67v8-88jf-4x6q
  3. 2026-10-09 Fix available: RHSA-2026:79717 · Red Hat
  4. 2026-10-09 Affected versions changed · Red Hat
  5. 2026-11-06 Affected versions changed · Red Hat

References

Patch 1

Advisory 1

Other 1

  • TI-2022-01156 Improper input validation in gzip, xz-utils CVSS 3.1HIGH 8.8
  • TI-2004-00544 gzexe in gzip 1.3.3 and earlier will execute an argument when the creation of a temp file… CVSS 2.0HIGH 10.0
  • TI-2010-00001 Integer underflow in the unlzw function in unlzw.c in gzip before 1.4 on 64-bit… CVSS 2.0MEDIUM 6.8
  • TI-2001-01181 Buffer overflows in gzip 1.3x, 1.2.4, and other versions might allow attackers to execute… CVSS 2.0HIGH 7.5
  • TI-2009-02508 The huft_build function in inflate.c in gzip before 1.3.13 creates a hufts (aka huffman)… CVSS 2.0MEDIUM 6.8
  • TI-2026-30386 Global Buffer Overflow in GNU gzip CVSS 4.0MEDIUM 6.9
See all 12 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences