GHSA-jmf4-m7j9-g72r
HIGHGHSA-jmf4-m7j9-g72r is a high-severity (CVSS 7.5) Server-Side Request Forgery (SSRF) vulnerability in github.com/rancher/fleet. O3 Security confirms whether GHSA-jmf4-m7j9-g72r is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Rancher Fleet has Unauthenticated Webhook: Regex Injection via Unsanitized Repository URL Components
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-jmf4-m7j9-g72r.
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-jmf4-m7j9-g72r 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 363,376 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/rancher/fleet🐹github.com/rancher/fleet🐹github.com/rancher/fleet🐹github.com/rancher/fleetReal-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
A vulnerability has been identified in Fleet when the webhook endpoint is configured without a secret; an attacker can forge webhook requests. The attacker doesn't need to know the specific repository or path configured in the GitRepo resource to make Fleet process these requests.
An attacker can exploit this vulnerability to cause the following impacts:
- Trigger continuous repository re-cloning, which increases network traffic and can deplete resources on the management cluster.
- Downgrade running services to any historical revision available in the remote Git repository. This risk applies if the attacker has read access to the target Git repository and knows its configured path.
Please consult the associated MITRE ATT&CK - Technique - T1499.004: Endpoint Denial of Service for further information about this category of attack.
Patches
To resolve this vulnerability, upgrade Fleet to a patched version. This upgrade version escapes the URL and path to the remote repository received from webhooks, which prevents regular expressions from being used as a replacement for the URL and path.
Patched versions of Fleet include releases v0.15.2, v0.14.6, 0.13.11, and v0.12.15.
Workarounds
If you can't upgrade to a fixed version, please make sure to only enable webhooks with a shared secret.
Credits
This security issue was reported by the following collaborators according to our responsible disclosure policy:
- Radisauskas Arnoldas from NATO and the NATO Cyber Security Centre (NCSC).
References
If you have any questions or comments about this advisory:
- Reach out to the SUSE Rancher Security team for security related inquiries.
- Open an issue in the Rancher repository.
- Verify with our support matrix and product support lifecycle.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/rancher/fleet | ≥ 0.15.0&&< 0.15.2 | 0.15.2 |
| 🐹Go | github.com/rancher/fleet | ≥ 0.14.0&&< 0.14.6 | 0.14.6 |
| 🐹Go | github.com/rancher/fleet | ≥ 0.13.0&&< 0.13.11 | 0.13.11 |
| 🐹Go | github.com/rancher/fleet | ≥ 0.12.0&&< 0.12.15 | 0.12.15 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rancher/fleet. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/rancher/fleet to 0.15.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-jmf4-m7j9-g72r 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 pinpoints whether GHSA-jmf4-m7j9-g72r is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-jmf4-m7j9-g72r. 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-jmf4-m7j9-g72r in your dependencies?
O3 detects GHSA-jmf4-m7j9-g72r across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.