CVE-2025-52993
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA race condition in Nix, Lix, and Guix package managers allows unprivileged users to change ownership of arbitrary files to the UID/GID of build users (nixbld* or guixbuild*). This enables privilege escalation by manipulating file ownership during build processes.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Identify installed package manager and versionRun: which nix lix guix 2>/dev/null; then for each found, run nix --version, lix --version, or guix --versionAffected if The installed version is older than Nix 2.24.15/2.26.4/2.28.4/2.29.1, Lix 2.91.2/2.92.2/2.93.1, or Guix 1.4.0-38.0e79d5b+
-
Check for build user accountsRun: getent passwd | grep -E '(nixbld|guixbuild)' or cat /etc/passwd | grep -E '(nixbld|guixbuild)'Affected if Accounts matching nixbld* or guixbuild* exist on the system, indicating build users are configured
-
Detect recent ownership changesRun: find / -perm -0004 -nouser -nogroup 2>/dev/null | head -20; also check audit logs with: auditctl -w /path -p a -k ownership if auditd is installedAffected if Files exist owned by UID/GID that do not map to any user/group, or unexpected ownership changes are logged, especially on system files
You are affected if a vulnerable version of Nix, Lix, or Guix is installed AND build user accounts exist on the system, making privilege escalation via ownership manipulation possible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to Nix 2.24.15+, 2.26.4+, 2.28.4+, or 2.29.1+; Lix 2.91.2+, 2.92.2+, or 2.93.1+; or Guix 1.4.0-38.0e79d5b+. Alternatively, restrict or audit build user permissions and monitor for suspicious ownership changes.
Nix 2.29.1+; Lix 2.93.1+; Guix 1.4.0-38.0e79d5b+
- Identify which package manager (Nix, Lix, or Guix) is in use in your environment
- For Nix: Upgrade to version 2.29.1 or later (or the latest 2.24.x/2.26.x/2.28.x patch that includes the fix)
- For Lix: Upgrade to version 2.93.1 or later (or the latest 2.91.x/2.92.x patch that includes the fix)
- For Guix: Upgrade to version 1.4.0-38.0e79d5b or later
- Verify the upgrade was successful by checking the installed version
- Restart any Nix/Lix/Guix daemon services to ensure the fixed version is active
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-52993 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-52993 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data