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GHSA-8w87-58w6-hfv8

CRITICAL

Rancher doesn't properly sanitize credentials in cluster template answers

Also known asCVE-2021-36783
Published
Mar 3, 2026
Updated
Mar 13, 2026
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed

EPSS Exploitation Probability

via FIRST.org ↗
0.6%probability of exploitation in next 30 days
Lower Risk46th percentile+0.17%
0.00%0.38%0.76%1.15%0.5%0.6%Dec 25Apr 26Jun 26

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.

Blast Radius

2 pkgs affected
🐹github.com/rancher/rancher🐹github.com/rancher/rancher

Real-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

It was discovered that in Rancher versions up to and including 2.5.12 and 2.6.3 there is a failure to properly sanitize credentials in cluster template answers. This failure can lead to plaintext storage and exposure of credentials, passwords and API tokens.

The exposed credentials are visible in Rancher to authenticated Cluster Owners, Cluster Members, Project Owners and Project Members on the endpoints /v1/management.cattle.io.clusters, /v3/clusters and /k8s/clusters/local/apis/management.cattle.io/v3/clusters.

Sensitive fields are now stripped from Clusters objects before the object is stored. For objects that existed before this security fix, a one-time migration happens on startup.

Important:

  • It is highly advised to review for potential leaked credentials in this scenario, and to change them if deemed necessary.
  • The final impact severity for confidentiality, integrity and availability is dependent on the permissions that the leaked credentials have on their own services.

Patches

Patched versions include releases 2.5.13, 2.6.4 and later versions.

Workarounds

Limit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.

Important: It is highly advised to review for potential leaked credentials in this scenario, and to change them if deemed necessary.

For more information

If you have any questions or comments about this advisory:

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
🐹Gogithub.com/rancher/rancher2.5.0&&< 2.5.132.5.13
🐹Gogithub.com/rancher/rancher2.6.0&&< 2.6.42.6.4

Detection & mitigation playbook

Open-source dependency
  1. Detect

    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.

  2. Fix

    Update github.com/rancher/rancher to 2.5.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8w87-58w6-hfv8 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 pinpoints whether GHSA-8w87-58w6-hfv8 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-8w87-58w6-hfv8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact It was discovered that in Rancher versions up to and including 2.5.12 and 2.6.3 there is a failure to properly sanitize credentials in cluster template answers. This failure can lead to plaintext storage and exposure of credentials, passwords and API tokens. The exposed credentials are visible in Rancher to authenticated `Cluster Owners`, `Cluster Members`, `Project Owners` and `Project Members` on the endpoints `/v1/management.cattle.io.clusters`, `/v3/clusters` and `/k8s/clusters/local/apis/management.cattle.io/v3/clusters`. Sensitive fields are now stripped from `Clusters` obj
O3 Security · Impact-Aware SCA

Is GHSA-8w87-58w6-hfv8 in your dependencies?

O3 detects GHSA-8w87-58w6-hfv8 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.