Xz: malicious code in distributed source
Priority CRITICAL 92CWE-506Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-506.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.909 99th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | xz | 5.6.0; 5.6.1 | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 10 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | Not affected | CNA |
| Red Hat | Red Hat JBoss Enterprise Application Platform 8 | — | — | Not affected | CNA |
- xz Vendor— Affected 5.6.0; 5.6.1 Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat JBoss Enterprise Application Platform 8 VendorRed Hat Affected — Fixed in — Not affected CNA
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Critical. Red Hat's page for this CVE →
Not affected: 6 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat JBoss Enterprise Application Platform 8
Timeline
- 2026-10-02 Threatist record created from CVE-2024-3094
- 2026-10-03 Alias added: GHSA-rxwq-x6h5-x525
References
Advisory 29
- https://access.redhat.com/security/cve/CVE-2024-3094
- RHBZ#2272210
- https://www.redhat.com/en/blog/urgent-security-alert-fedora-41-and-rawhide-users
- https://arstechnica.com/security/2024/03/backdoor-found-in-widely-used-linux-utility-breaks-encrypted-ssh-connections/
- https://aws.amazon.com/security/security-bulletins/AWS-2024-002/
- https://boehs.org/node/everything-i-know-about-the-xz-backdoor
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1068024
- https://bugs.gentoo.org/928134
- https://bugzilla.suse.com/show_bug.cgi?id=1222124
- https://discourse.nixos.org/t/cve-2024-3094-malicious-code-in-xz-5-6-0-and-5-6-1-tarballs/42405
- https://gist.github.com/thesamesam/223949d5a074ebc3dce9ee78baad9e27
- https://github.com/advisories/GHSA-rxwq-x6h5-x525
- https://github.com/karcherm/xz-malware
- https://gynvael.coldwind.pl/?lang=en&id=782
- https://lists.debian.org/debian-security-announce/2024/msg00057.html
- https://lists.freebsd.org/archives/freebsd-security/2024-March/000248.html
- https://lwn.net/Articles/967180/
- https://news.ycombinator.com/item?id=39865810
- https://openssf.org/blog/2024/03/30/xz-backdoor-cve-2024-3094/
- https://security-tracker.debian.org/tracker/CVE-2024-3094
- https://security.alpinelinux.org/vuln/CVE-2024-3094
- https://security.archlinux.org/CVE-2024-3094
- https://tukaani.org/xz-backdoor/
- https://twitter.com/LetsDefendIO/status/1774804387417751958
- https://ubuntu.com/security/CVE-2024-3094
- https://www.cisa.gov/news-events/alerts/2024/03/29/reported-supply-chain-compromise-affecting-xz-utils-data-compression-library-cve-2024-3094
- https://www.darkreading.com/vulnerabilities-threats/are-you-affected-by-the-backdoor-in-xz-utils
- https://www.tenable.com/blog/frequently-asked-questions-cve-2024-3094-supply-chain-backdoor-in-xz-utils
- https://xeiaso.net/notes/2024/xz-vuln/
More Red Hat vulnerabilities
- TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
- TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
- TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
Sources
- CVE-2024-3094 · CVE Program
- CVE-2024-3094 · NVD
- FIRST EPSS
- GHSA-rxwq-x6h5-x525 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-3094 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences