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).
History

Tue, 05 May 2026 04:15:00 +0000

Type Values Removed Values Added
First Time appeared Lix Project
Lix Project lix
Nixos
Nixos nix
Vendors & Products Lix Project
Lix Project lix
Nixos
Nixos nix

Tue, 05 May 2026 02:45:00 +0000

Type Values Removed Values Added
Title Stack-to-Heap Overflow in Nix Archive Parser Allows Privilege Escalation and Arbitrary Code Execution

Tue, 05 May 2026 01:15:00 +0000

Type Values Removed Values Added
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).
Weaknesses CWE-674
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-05-05T00:37:42.535Z

Reserved: 2026-05-05T00:29:44.087Z

Link: CVE-2026-44028

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-05T01:16:06.983

Modified: 2026-05-05T01:16:06.983

Link: CVE-2026-44028

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-05T04:00:11Z