GHSA-6xv5-86q9-7xr8 — filepath-securejoin
Fix: cyphar/filepath-securejoin#9GHSA-6xv5-86q9-7xr8 is a security vulnerability in github.com/cyphar/filepath-securejoin. A fix is available for github.com/cyphar/filepath-securejoin — see the affected versions and patch details below.
SecureJoin: on windows, paths outside of the rootfs could be inadvertently produced
Real-World Exposure
github.com/cyphar/filepath-securejoinReal-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
Impact
For Windows users of github.com/cyphar/filepath-securejoin, until v0.2.4 it was possible for certain rootfs and path combinations (in particular, where a malicious Unix-style /-separated unsafe path was used with a Windows-style rootfs path) to result in generated paths that were outside of the provided rootfs.
It is unclear to what extent this has a practical impact on real users, but given the possible severity of the issue we have released an emergency patch release that resolves this issue.
Thanks to @pjbgf for discovering, debugging, and fixing this issue (as well as writing some tests for it).
Patches
c121231e1276e11049547bee5ce68d5a2cfe2d9b is the patch fixing this issue. v0.2.4 contains the fix.
Workarounds
Users could use filepath.FromSlash() on all unsafe paths before passing them to filepath-securejoin.
References
See #9.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cyphar/filepath-securejoin | all versions | 0.2.4go get github.com/cyphar/filepath-securejoin@v0.2.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cyphar/filepath-securejoin, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cyphar/filepath-securejoin to 0.2.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6xv5-86q9-7xr8 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 GHSA-6xv5-86q9-7xr8 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-6xv5-86q9-7xr8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6xv5-86q9-7xr8 in your dependencies?
O3 Security finds GHSA-6xv5-86q9-7xr8 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.