GHSA-cr2j-534f-mf3g — apptainer
MEDIUMGHSA-cr2j-534f-mf3g is a medium-severity (CVSS 4.8) Path Traversal vulnerability in github.com/apptainer/apptainer. A fix is available for github.com/apptainer/apptainer — see the affected versions and patch details below.
Apptainer has incorrect path matching for 'limit container paths' directive
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 GHSA-cr2j-534f-mf3g.
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
GHSA-cr2j-534f-mf3g 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 377,166 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/apptainer/apptainerReal-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
The limit container paths directive in apptainer.conf is intended to allow a system administrator limit the paths from which containers can be run, under setuid mode. Due to incorrect matching of a path string, sibling directories with similar names may incorrectly be allowed.
For example, the configuration:
limit container paths = /data/safe
Will also allow containers in /data/safe-but-unsafe to be run.
Patches
The issue is patched in apptainer version 1.5.1.
Workarounds
If developers do not use setuid mode or do not use the limit container paths functionality, then this issue does not affect their installation. Note that, as documented [1], if user namespaces are allowed for unrestricted use then this functionality does not stop users from running any container of their choice.
If developers do use the limit container paths functionality they are advised to update.
Credit
This vulnerability was discovered and disclosed to the Apptainer project by Dave Trudgian of Sylabs.
Resources
[1] https://apptainer.org/docs/admin/latest/configfiles.html#limiting-container-execution
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/apptainer/apptainer | all versions | 1.5.1go get github.com/apptainer/apptainer@v1.5.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/apptainer/apptainer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/apptainer/apptainer to 1.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cr2j-534f-mf3g 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-cr2j-534f-mf3g can be triaged on real exposure rather than presence alone.
Tailored to GHSA-cr2j-534f-mf3g. 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-cr2j-534f-mf3g in your dependencies?
O3 Security finds GHSA-cr2j-534f-mf3g across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.