Rancher API and cluster.management.cattle.io object vulnerable to plaintext storage and exposure of credentials

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.9 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

• CVE-2021-36782: 4.17% estimated exploitation activity in the next 30 days; percentile 90.91 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact An issue was discovered in Rancher versions up to and including 2.5.15 and 2.6.6 where sensitive fields, like passwords, API keys and Rancher's service account token (used to provision clusters), were stored in plaintext directly on Kubernetes objects like Clusters, for example cluster.management.cattle.io. Anyone with read access to those objects in the Kubernetes API could retrieve the plaintext version of those sensitive data. The exposed credentials are visible in Rancher to authenticated Cluster Owners, Cluster Members, Project Owners, Project Members and User Base on the endpoints: - /v1/management.cattle.io.catalogs - /v1/management.cattle.io.cluster - /v1/management.cattle.io.clustertemplates - /v1/management.cattle.io.notifiers - /v1/project.cattle.io.sourcecodeproviderconfig - /k8s/clusters/local/apis/management.cattle.io/v3/catalogs - /k8s/clusters/local/apis/management.cattle.io/v3/clusters - /k8s/clusters/local/apis/management.cattle.io/v3/clustertemplates -…

Published by the source

23 Sep 2022, 18:11 UTC

Last modified by the source

31 Jan 2023, 05:04 UTC

Source last checked

26 Oct 2026, 14:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-g7j7-h4q8-8w2f

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# Patch Next advisory brief: CVE-2021-36782

Advisory: Rancher API and cluster.management.cattle.io object vulnerable to plaintext storage and exposure of credentials
IDs: CVE-2021-36782, GHSA-g7j7-h4q8-8w2f
Record: https://patchnext.com/advisories/cve-2021-36782 (revision 1, source checked 26 Oct 2026, 14:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/rancher/rancher 2.6.7, 2.5.16. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/rancher/rancher: affected >= 2.5.0, < 2.5.16; >= 2.6.0, < 2.6.7; fixed in 2.6.7, 2.5.16

## Suggested inspection (read-only)
- Go github.com/rancher/rancher: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/rancher/rancher.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-g7j7-h4q8-8w2f (GitHub-reviewed advisory GHSA-g7j7-h4q8-8w2f lists affected ranges: Go github.com/rancher/rancher >=2.5.0 =2.6.0 <2.6.7)

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