CVE-2026-44028: NixOS Nix · Uncontrolled Recursion
Affects NixOS NixSource CVE Database V5
Not known to be exploited · CVSS 7.5 High · fixed in 2.34.7 : patch NixOS Nix soon.
Data as of 1 Nov 2026, 22:58 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.34.7, 2.33.6, 2.32.8 +7
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 1 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| NixOSNix | Affected
| Fixed in
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| NixOSNix | Affected
| Fixed in
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| NixOSNix | Affected
| Fixed in
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| NixOSNix | Affected
| Fixed in
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| NixOSNix | Affected
| Fixed in
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| NixOSNix | Affected
| Fixed in
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AI-suggested
Fixed versions of Nix and Lix have been released (Nix 2.34.7 and later, Lix 2.95.2 and later). Users should upgrade to these versions or later to remediate this vulnerability. No vendor advisory content is provided here, but the description explicitly lists fixed versions. Until upgraded, restricting access to the Nix daemon via the allowed-users setting can reduce exposure. Patch status is confirmed by the provided fixed version information.
Description
An issue was discovered in Nix before 2.34.7 and Lix before 2.95.2. Unbounded recursion in the NAR (Nix Archive) parser could lead to a stack-to-heap overflow when the parser is run on a coroutine stack. The stack is allocated without a guard page, which means that a stack overflow could overwrite memory on the heap and could allow arbitrary code execution as the Nix daemon (run as root in multi-user installations) if ASLR hardening is bypassed. This can be exploited by all users able to connect to the daemon (e.g., in Nix, this is configurable via the allowed-users setting, defaulting to all users). The fixed versions are 2.34.7, 2.33.6, 2.32.8, 2.31.5, 2.30.5, 2.29.4, and 2.28.7 for Nix (introduced in 2.24.4); and 2.95.2, 2.94.2, and 2.93.4 for Lix (introduced in 2.93.0).
References
- discourse.nixos.org/t/security-advisory-local-privilege-escalation-in-lix-and-nix/77407 (opens in a new tab)
- github.com/NixOS/nix/security/advisories/GHSA-vh5x-56v6-4368 (opens in a new tab)
- openwall.com/lists/oss-security/2026/05/04/33 (opens in a new tab)
- openwall.com/lists/oss-security/2026/05/04/32 (opens in a new tab)
- lix.systems/blog/2026-05-05-lix-unsigned-integer-overflow/ (opens in a new tab)