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TI-2026-27493 Aliases CVE-2026-35355GHSA-239g-2685-54x3

uutils coreutils install Arbitrary File Overwrite via Symlink TOCTOU Race

Priority MEDIUM 61CWE-367Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
None · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

The install utility in uutils coreutils is vulnerable to a Time-of-Check to Time-of-Use (TOCTOU) race condition during file installation. The implementation unlinks an existing destination file and then recreates it using a path-based operation without the O_EXCL flag. A local attacker can exploit the window between the unlink and the subsequent creation to swap the path with a symbolic link, allowing them to redirect privileged writes to overwrite arbitrary system files.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00118 1st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed coreutils (Uutils): 0.6.0uu_install (crates.io): 0.6.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
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
Uutilscoreutilsbefore 0.6.00.6.0Patch availableCNA
—uu_install (crates.io)before 0.6.00.6.0Patch availableGHSA-239g-2685-54x3
  • coreutils VendorUutils Affected before 0.6.0 Fixed in 0.6.0 Patch available CNA
  • uu_install (crates.io) Vendor— Affected before 0.6.0 Fixed in 0.6.0 Patch available GHSA-239g-2685-54x3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:uutils:coreutils:*:*:*:*:*:rust:*:*before 0.6.0VulnerableUutils
  • cpe:2.3:a:uutils:coreutils:*:*:*:*:*:rust:*:* Versions before 0.6.0 Vulnerable ·Uutils

Remediation

  • Fix · CNA coreutils (Uutils) Fixed in 0.6.0
  • Fix · GHSA-239g-2685-54x3 uu_install (crates.io) Fixed in 0.6.0 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Advisory ·

    Uutils coreutils — github.com/uutils/coreutils/releases/tag/0.6.0

    12 records Highest priority Priority MEDIUM 3 MEDIUM, 9 LOW

    Other records, highest priority first

    • TI-2026-27504 uutils coreutils printenv Security Inspection Bypass via UTF-8 EnforcementPriority MEDIUM 54
    • TI-2026-27484 uutils coreutils comm Silent Data Corruption via Lossy UTF-8 NormalizationPriority MEDIUM 49
    • TI-2026-27476 uutils coreutils chmod Path Traversal Bypass of --preserve-rootPriority LOW 33
    Show all 12 records → Advisory →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-35355
  2. 2026-10-03 Alias added: GHSA-239g-2685-54x3

References

Exploit 1

Advisory 2

Other 3

  • TI-2026-27506 uutils coreutils chroot Local Privilege Escalation and chroot Escape in via Name Service Switch (NSS) Injection CVSS 3.1HIGH 7.2
  • TI-2026-27498 uutils coreutils touch Arbitrary File Truncation via TOCTOU Race Condition CVSS 3.1MEDIUM 6.3
  • TI-2026-27488 uutils coreutils cp Unexpected Privileged Executable Creation with -p CVSS 3.1MEDIUM 6.6
  • TI-2026-27502 uutils coreutils mv Arbitrary File Overwrite via Cross-Device TOCTOU Race Condition CVSS 3.1MEDIUM 6.3
  • TI-2026-27511 uutils coreutils ln Local Denial of Service via Improper Handling of Non-UTF-8 Filenames CVSS 3.1MEDIUM 5.5
  • TI-2026-27486 uutils coreutils sort Local Denial of Service via Forced UTF-8 Parsing CVSS 3.1MEDIUM 5.5
See all 43 →

Sources

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