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CVE-2025-52993VulnerabilityPublished

CVE-2025-52993: NixOS Nix · Race Condition

Affects NixOS NixSource CVE Database V5

0

Not known to be exploited · CVSS 5.6 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score
5.6Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 Jun 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Affected software

ProductAffectedFixed in
NixOS NixAffected
  • =0
  • =2.25.0
  • =2.27.0
  • =2.29.0
Fixed in–

AI-suggested

European organizations should prioritize upgrading affected package managers to the patched versions: Nix 2.24.15, 2.26.4, 2.28.4, or 2.29.1 and later; Lix 2.91.2, 2.92.2, or 2.93.1 and later; and Guix 1.4.0-38.0e79d5b or later. Until patches are applied, organizations should restrict local access to build environments to trusted personnel only and implement strict access controls and monitoring on build user accounts (nixbld*, guixbuild*). Employing file integrity monitoring on build directories can help detect unauthorized ownership changes. Additionally, segregating build environments from general user environments and enforcing the principle of least privilege can reduce the attack surface. Incorporating runtime monitoring to detect anomalous file ownership changes or unexpected build user activity can provide early warning of exploitation attempts. Finally, organizations should review and harden their DevOps pipeline security, including secure credential management and audit logging, to detect and respond to suspicious activities promptly.

Description

A race condition in the Nix, Lix, and Guix package managers enables changing the ownership of arbitrary files to the UID and GID of the build user (e.g., nixbld* or guixbuild*). This affects Nix before 2.24.15, 2.26.4, 2.28.4, and 2.29.1; Lix before 2.91.2, 2.92.2, and 2.93.1; and Guix before 1.4.0-38.0e79d5b.

References

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