CVE-2021-36783: Github.com/rancher/rancher Rancher Doesn't Properly Sanitize Credentials Vulnerability
CRITICALCVE-2021-36783 is a CRITICAL (CVSS 9.9) rancher doesn't properly sanitize credentials vulnerability (CWE-312: Cleartext Storage of Sensitive Information) affecting Github.com/rancher/rancher libraries in the Go ecosystem. The issue involves rancher doesn't properly sanitize credentials in cluster template answers. Remediation is available by upgrading affected packages to version 2.5.13, 2.6.4.
CVE-2021-36783 at a Glance
Security Impact
CVSS: 9.9
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H).
How to Fix CVE-2021-36783
To remediate this vulnerability, upgrade all affected Github.com/rancher/rancher dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade github.com/rancher/rancher to 2.5.13
Upgrade github.com/rancher/rancher to 2.6.4
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/rancher/rancher
How to Check if You Are Affected
To determine whether your application is affected by CVE-2021-36783, inspect your project dependencies for Github.com/rancher/rancher:
inspect dependencies for github.com/rancher/rancher
Analyze the terminal output to locate any version of Github.com/rancher/rancher in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.5.13), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-312: Cleartext Storage of Sensitive Information, where the product stores sensitive information in cleartext within a resource that might be accessible to another control sphere. In Github.com/rancher/rancher, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-36783 Affected Github.com/rancher/rancher Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/rancher/rancher
|
Go |
≥ 2.5.0
< 2.5.13
|
2.5.13
|
|
github.com/rancher/rancher
|
Go |
≥ 2.6.0
< 2.6.4
|
2.6.4
|
References
Frequently Asked Questions
What is CVE-2021-36783?
Which Github.com/rancher/rancher versions are affected?
What version fixes CVE-2021-36783?
Is github.com/rancher/rancher affected?
What is the CVSS score of CVE-2021-36783?
What CWE is associated with CVE-2021-36783?
How can I check Go dependencies for CVE-2021-36783?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-8w87-58w6-hfv8",
"modified" : "2026-03-03T14:49:34Z",
"published" : "2026-03-03T14:49:34Z",
"aliases" : [ "CVE-2021-36783" ],
"summary" : "Rancher doesn't properly sanitize credentials in cluster template answers",
"details" : "### Impact\n\nIt 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.\n\nThe 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`.\n\nSensitive 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.\n\n**Important:**\n- It is highly advised to review for potential leaked credentials in this scenario, and to change them if deemed necessary.\n- The final impact severity for confidentiality, integrity and availability is dependent on the permissions that the leaked credentials have on their own services.\n\n### Patches\nPatched versions include releases 2.5.13, 2.6.4 and later versions.\n\n### Workarounds\nLimit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.\n\n**Important:** It is highly advised to review for potential leaked credentials in this scenario, and to change them if deemed necessary.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Reach out to [SUSE Rancher Security team](https://github.com/rancher/rancher/security/policy) for security related inquiries.\n* Open an issue in [Rancher](https://github.com/rancher/rancher/issues/new/choose) repository.\n* Verify our [support matrix](https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/) and [product support lifecycle](https://www.suse.com/lifecycle/).",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/rancher/rancher"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.5.0"
}, {
"fixed" : "2.5.13"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 2.5.12"
}
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/rancher/rancher"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "2.6.0"
}, {
"fixed" : "2.6.4"
} ]
} ],
"database_specific" : {
"last_known_affected_version_range" : "<= 2.6.3"
}
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/rancher/rancher/security/advisories/GHSA-8w87-58w6-hfv8"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-36783"
}, {
"type" : "WEB",
"url" : "https://bugzilla.suse.com/show_bug.cgi?id=1193990"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/rancher/rancher"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-200", "CWE-312", "CWE-522" ],
"severity" : "CRITICAL",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-03T14:49:34Z",
"nvd_published_at" : "2022-09-07T09:15:00Z"
}
}