Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0.
CVE-2026-64846
LOWPre-NVD 2.82.8—Trending — 3 sources updated this week
EchelonGraph scoreMEDIUM confidence
This low-severity CVE scores 2.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.1%, top 100% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
2.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 2.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 2.8
- EG Score
- 2.8(medium)
- EG Risk
- 13(Track)EG Risk 13/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity28% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 0%
- KEV
- Not listed
Published
August 20, 2026
Last Modified
August 20, 2026
References (3)
- security-advisories@githubhttps://github.com/NixOS/nix/commit/26679828f74ee6e82a4100904e6361f993ff5390
- security-advisories@githubhttps://github.com/NixOS/nix/pull/15401
- security-advisories@githubhttps://github.com/NixOS/nix/security/advisories/GHSA-6h4g-g5j9-fm5f
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 8× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-25 13:49 UTCEPSS rescore
- 2026-08-23 23:05 UTCEG score recompute
- 2026-08-21 23:49 UTCEPSS rescore
- 2026-08-20 20:20 UTCEG score recompute
- 2026-08-20 19:37 UTCEG score recompute
- 2026-08-20 17:34 UTCEG score recompute
- 2026-08-20 16:33 UTCEG score recompute
- 2026-08-20 16:32 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-64846?
CVE-2026-64846 is a low vulnerability published on August 20, 2026. Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to…
When was CVE-2026-64846 disclosed?
CVE-2026-64846 was first published in the National Vulnerability Database on August 20, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64846 actively exploited?
CVE-2026-64846 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 99.6% of all scored CVEs.
What is the CVSS score of CVE-2026-64846?
CVE-2026-64846 has a CVSS v3 base score of 2.8 (NVD).
How do I remediate CVE-2026-64846?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64846, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-64846
Is Your Infrastructure Affected by CVE-2026-64846?
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