Cyber Resilience

CVE-2026-35355

Race Condition in Uutils Coreutils ≤ 0.6.0

Public PoCRace Condition
Published
22 April 2026
Modified
27 April 2026
Patch / advisory
CVSS Score v3.1 6.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0012 2th percentile
Risk Priority 40 floored blend · peak EPSS

Summary

CVE-2026-35355 is a medium-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Uutils Coreutils. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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.

EU & UK References

Vulnerability Data

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…

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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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

TOCTOU symlink race in privileged install utility directly enables local arbitrary file overwrite for privilege escalation.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-35352Same product: Uutils Coreutils
CVE-2026-35356Same product: Uutils Coreutils
CVE-2026-35362Same product: Uutils Coreutils
CVE-2026-35359Same product: Uutils Coreutils
CVE-2026-35370Same product: Uutils Coreutils
CVE-2026-35372Same product: Uutils Coreutils
CVE-2026-35360Same product: Uutils Coreutils
CVE-2026-35353Same product: Uutils Coreutils
CVE-2026-35361Same product: Uutils Coreutils
CVE-2026-35368Same product: Uutils Coreutils

Affected Assets

uutils
coreutils
≤ 0.6.0

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-6 Least Privilege
  • AC-3 Access Enforcement
  • CM-5 Access Restrictions for Change
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V15.4.2
  • V17.2.6

Mitigating Controls (NIST 800-53 r5) AI

prevent

Least privilege directly limits the install utility's ability to overwrite arbitrary system files even if the TOCTOU symlink swap succeeds.

prevent

Access enforcement can block the redirected write by ensuring the recreated file object is only writable under the original intended path semantics.

prevent

Access restrictions for change can restrict who may perform the privileged unlink/create operations that the race condition exploits.

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards and reviews that prevent TOCTOU race conditions.

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.

none

Reliable, synchronized time across systems narrows the exploitable window in which a resource state can change between a security check and its use.

References