CVE-2026-54250 — k3s
MEDIUMCVE-2026-54250 is a medium-severity (CVSS 5.8) Path Traversal vulnerability in github.com/k3s-io/k3s. A fix is available for github.com/k3s-io/k3s — see the affected versions and patch details below.
K3s: ZIP Archive Path Traversal Vulnerability in etcd Snapshot Decompression
Exploitation Status
No confirmed exploitation observed yet
- 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 CVE-2026-54250.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/k3s-io/k3s🐹github.com/k3s-io/k3s🐹github.com/k3s-io/k3sReal-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
Summary
A path traversal vulnerability exists in K3s's etcd snapshot decompression functionality. Zip files containing archive members with maliciously crafted names (e.g., ../../../../etc/password) can be written to arbitrary locations on the filesystem when an administrator restores the archive as a compressed etcd snapshot.
Mitigations
- Enable golang's built-in insecure path protections when restoring snapshots by setting the
GODEBUGenvironment variable:GODEBUG=zipinsecurepath=0 k3s server --cluster-reset --cluster-reset-restore-path=/path/to/snapshot.zip - Manually extract the snapshot from the zip archive before restoring it. If the snapshot to be restored does not end with
.zip, the vulnerable extraction code will not be executed.
Additional Notes
Administrators should be aware of the cautions noted in the "Security" section of the documentation on Restoring Snapshots.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/k3s-io/k3s | ≥ 1.35.0-rc1&&< 1.35.3 | 1.35.3go get github.com/k3s-io/k3s@v1.35.3 |
| 🐹Go | github.com/k3s-io/k3s | ≥ 1.34.0-rc1&&< 1.34.6 | 1.34.6go get github.com/k3s-io/k3s@v1.34.6 |
| 🐹Go | github.com/k3s-io/k3s | all versions | 1.33.10go get github.com/k3s-io/k3s@v1.33.10 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/k3s-io/k3s, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/k3s-io/k3s to 1.35.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-54250 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2026-54250 in your dependencies?
Find it across Go, including transitive dependencies.