Xz: malicious code in distributed sourceGHSA-rxwq-x6h5-x525
CRITICALGHSA-rxwq-x6h5-x525 is a critical-severity (CVSS 10) CWE-506 vulnerability. 45 public exploit references exist, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-rxwq-x6h5-x525.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-rxwq-x6h5-x525 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 395,492 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
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.
Affected Products
xztukaaniResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Malicious code was discovered in the upstream tarballs of xz, starting w…
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for GHSA-rxwq-x6h5-x525 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-rxwq-x6h5-x525 in your dependencies?
Find it across , including transitive dependencies.