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Fencer Vulns
high 7.5

CVE-2026-44028 json

An issue was discovered in Nix before 2.34.7 and Lix before 2.95.2.

published 2026-05-05 6 mo ago modified 2026-10-26 13 d ago also EUVD-2026-27163

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

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).

Patch / fix

  • NixOS Nix 2.28.7, 2.29.4, 2.30.5, 2.31.5, 2.32.8, 2.33.6, 2.34.7
  • Lix Project Lix 2.93.4, 2.94.2, 2.95.2
  • nix Debian 14 2.34.8+dfsg-1

debian advisories DEBIAN-CVE-2026-44028

  • rust hummingbird 1 1.95.0-2.hum1
  • rustfmt hummingbird 1 1.95.0-2.hum1
  • rust-gdb hummingbird 1 1.95.0-2.hum1
  • rust-src hummingbird 1 1.95.0-2.hum1
  • rust-lldb hummingbird 1 1.95.0-2.hum1
  • rust-analyzer hummingbird 1 1.95.0-2.hum1
  • rust-debugger-common hummingbird 1 1.95.0-2.hum1
  • rust-std-static-wasm32-wasip1 hummingbird 1 1.95.0-2.hum1

red hat advisories RHSA-2026:9438RHSA-2026:7046RHSA-2026:10208RHSA-2026:10999

  • nix openSUSE Tumbleweed 2.34.7-1.1

opensuse advisories openSUSE-SU-2026:10696-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-44028 updated cvss 7.8

nix: coroutine stack-to-heap overflow via unbounded recursion in NAR directory parser

  • Red Hat Hardened Images rust 1.95.0-2.hum1, cargo 1.95.0-2.hum1, ruff 0.15.11-1.hum1, chunkah 0.4.0-1.hum1, bootc 1.14.0-0.1.1.hum1, python3-ruff 0.15.11-1.hum1, +1 more
    fixed: vendor fix RHSA-2026:7046

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
6 mo ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N

Affected products

  • NixOS Nix
  • Lix Project Lix

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.