GHSA-4h45-jpvh-6p5j is a high-severity (CVSS 8.2) CWE-770 vulnerability in github.com/rancher/rancher. O3 Security confirms whether GHSA-4h45-jpvh-6p5j is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Rancher affected by unauthenticated Denial of Service
Real-World Exposure
github.com/rancher/rancher🐹github.com/rancher/rancher🐹github.com/rancher/rancher🐹github.com/rancher/rancher🐹github.com/rancher/rancherReal-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 within Rancher Manager in which it did not enforce request body size limits on certain public (unauthenticated) and authenticated API endpoints. This allows a malicious user to exploit this by sending excessively large payloads, which are fully loaded into memory during processing. This could result in:
- Denial of Service (DoS): The server process may crash or become unresponsive when memory consumption exceeds available resources.
- Unauthenticated and authenticated exploitation: While the issue was initially observed in unauthenticated
/v3-public/*endpoints, the absence of request body size limits also affected several authenticated APIs, broadening the potential attack surface. It's worth noting that other areas in Rancher do implement safeguards: requests proxied to Kubernetes APIs are subject to built-in size limits enforced by the Kubernetes API server itself, and Norman-based endpoints parse input with predefined size caps. However, the absence of similar protections in other Rancher APIs increased the risk of denial-of-service (DoS) scenarios in certain contexts.
By sending large binary or text payloads to vulnerable endpoints, a malicious actor could disrupt Rancher’s availability, impacting both administrative and user operations across managed clusters.
Please consult the associated MITRE ATT&CK - Technique - Network Denial of Service for further information about this category of attack.
Patches
This vulnerability is addressed by adding a default limit of 1MiB and a setting in case this value needs to be increased.
Patched versions of Rancher include releases v2.12.1, v2.11.5, v2.10.9 and v2.9.12.
Workarounds
If you can't upgrade to a fixed version, please make sure that you are manually setting the request body size limits. For example, using nginx-ingress controller and only allowing requests via the ingress. For reference on how to configure the limit manually, please consult the Knowledge Base.
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/rancher | ≥ 2.12.0&&< 2.12.1 | 2.12.1 |
| 🐹Go | github.com/rancher/rancher | ≥ 2.11.0&&< 2.11.5 | 2.11.5 |
| 🐹Go | github.com/rancher/rancher | ≥ 2.10.0&&< 2.10.9 | 2.10.9 |
| 🐹Go | github.com/rancher/rancher | ≥ 2.9.0&&< 2.9.11 | 2.9.11 |
| 🐹Go | github.com/rancher/rancher | all versions | 0.0.0-20250813072957-aee95d4e2a41 |
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/rancher. 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/rancher to 2.12.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4h45-jpvh-6p5j 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-4h45-jpvh-6p5j 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-4h45-jpvh-6p5j. 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-4h45-jpvh-6p5j in your dependencies?
O3 detects GHSA-4h45-jpvh-6p5j across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.