CVE-2025-58058 is a medium-severity (CVSS 5.3) CWE-770 vulnerability in github.com/ulikunitz/xz. A fix is available for github.com/ulikunitz/xz — see the affected versions and patch details below.
github.com/ulikunitz/xz leaks memory when decoding a corrupted multiple LZMA archives
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-58058 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/ulikunitz/xzReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
xz is a pure golang package for reading and writing xz-compressed files. Prior to version 0.5.14, it is possible to put data in front of an LZMA-encoded byte stream without detecting the situation while reading the header. This can lead to increased memory consumption because the current implementation allocates the full decoding buffer directly after reading the header. The LZMA header doesn't include a magic number or has a checksum to detect such an issue according to the specification. Note that the code recognizes the issue later while reading the stream, but at this time the memory allocation has already been done. This issue has been patched in version 0.5.14.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/ulikunitz/xz | all versions | 0.5.15go get github.com/ulikunitz/xz@v0.5.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/ulikunitz/xz, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/ulikunitz/xz to 0.5.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-58058 is resolved across your whole dependency graph.
Workarounds
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-58058 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-58058. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| multicluster engine for Kubernetes 2.8 | multicluster-engine/assisted-service-8-rhel8:1781539691 | RHSA-2026:26257 |
| multicluster engine for Kubernetes 2.8 | multicluster-engine/assisted-service-9-rhel9:1781539725 | RHSA-2026:26254 |
| Red Hat Openshift Data Foundation 4.22 | odf4/cephcsi-rhel9:1782932114 | RHSA-2026:37387 |
Frequently Asked Questions
Is CVE-2025-58058 in your dependencies?
O3 Security finds CVE-2025-58058 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.