CVE-2026-44029Network attack vector

Arbitrary file writes via absolute archive paths

Published May 5, 2026 · Updated May 5, 2026

Absolute path traversal in Nix allows remote attackers to write arbitrary files when a user unpacks a crafted archive. The nix-prefetch-url --unpack and nix store prefetch-file --unpack commands accept absolute archive entry paths and write them outside the extraction root. Exploitation requires a packager to process an untrusted archive; sandboxed builtin:unpack-channel builds cannot write to the host filesystem.

CVSS severity4.3
Medium
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Absolute path traversal in Nix allows remote attackers to write arbitrary files when a user unpacks a crafted archive. The nix-prefetch-url --unpack and nix store prefetch-file --unpack commands accept absolute archive entry paths and write them outside the extraction root. Exploitation requires a packager to process an untrusted archive; sandboxed builtin:unpack-channel builds cannot write to the host filesystem.

The record

CVE
CVE-2026-44029
Published
May 5, 2026
Updated
May 5, 2026
Vendor
NixOS
Product
Nix
Classifications
CWE-36, CAPEC-597, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 5, 2026CVE publishedPublication date reported by the CVE source.
  2. May 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.24.7 <2.28.7
  2. Affected versionversion=2.29.0 <2.29.4
  3. Affected versionversion=2.30.0 <2.30.5
  4. Affected versionversion=2.31.0 <2.31.5
  5. Affected versionversion=2.32.0 <2.32.8
  6. Affected versionversion=2.33.0 <2.33.6
  7. Affected versionversion=2.34.0 <2.34.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

NixOS · Nixversion=2.24.7 <2.28.7; version=2.29.0 <2.29.4; version=2.30.0 <2.30.5; version=2.31.0 <2.31.5; version=2.32.0 <2.32.8; version=2.33.0 <2.33.6; version=2.34.0 <2.34.7

Published CVSS scores

5.3MITRECVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
4.3NixOSCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-36Absolute Path Traversal
CAPEC-597Absolute Path Traversal
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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