How severe is CVE-2021-36775?

CVE-2021-36775 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-36775?

CVE-2021-36775 affects the following packages: github.com/rancher/rancher (Go), github.com/rancher/rancher (Go), github.com/rancher/rancher (Go). Ecosystems affected: Go.

How do I fix CVE-2021-36775?

Update github.com/rancher/rancher to 2.4.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-36775 is resolved across your whole dependency graph.

How do I detect CVE-2021-36775 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rancher/rancher, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-36775 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2021-36775 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-36775 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-36775?

CVE-2021-36775 has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 62th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-36775?

CVE-2021-36775 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-36775 published, and has it been updated?

CVE-2021-36775 was published on April 4, 2022 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹

🐹 Go

Not in CISA KEV

HIGH severity

CVE-2021-36775 — rancher

HIGH

CVE-2021-36775 is a high-severity (CVSS 8.8) CWE-284 vulnerability in github.com/rancher/rancher. A fix is available for github.com/rancher/rancher — see the affected versions and patch details below.

Rancher's Failure to delete orphaned role bindings does not revoke project level access from group based authentication

Also known asGHSA-28g7-896h-695vGO-2024-2760

Published

Apr 4, 2022

Updated

Oct 24, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs62th percentile — riskier than 62% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

3 pkgs affected

🐹github.com/rancher/rancher🐹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

This vulnerability only affects customers using group based authentication in Rancher versions up to and including 2.4.17, 2.5.11 and 2.6.2.

When removing a Project Role associated to a group from a project, the bindings that grant access to cluster scoped resources for those subjects do not get deleted. This happens due to an incomplete authorization logic check. A user who is a member of an affected group with authenticated access to Rancher could use this to access resources they should no longer have access to. The exposure level will depend on the original permission level granted to the affected project role.

Patches

Patched versions include releases 2.4.18, 2.5.12, 2.6.3 and later versions.

Workarounds

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

References

Cluster and project roles documentation for Rancher 2.6, 2.5 and 2.4.

For more information

If you have any questions or comments about this advisory:

Reach out to SUSE Rancher Security team for security related inquiries.
Open an issue in Rancher repository.
Verify our support matrix and product support lifecycle.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/rancher/rancher`	all versions	2.4.18`go get github.com/rancher/rancher@v2.4.18`
🐹Go	`github.com/rancher/rancher`	≥ 2.5.0&&< 2.5.12	2.5.12`go get github.com/rancher/rancher@v2.5.12`
🐹Go	`github.com/rancher/rancher`	≥ 2.6.0&&< 2.6.3	2.6.3`go get github.com/rancher/rancher@v2.6.3`

Affected Products

1 product · 3 configurations

Application

rancherrancher

≥ 2.6.0 && < 2.6.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/rancher/rancher, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/rancher/rancher to 2.4.18 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-36775 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### Impact This vulnerability only affects customers using group based authentication in Rancher versions up to and including 2.4.17, 2.5.11 and 2.6.2. When removing a Project Role associated to a group from a project, the bindings that grant access to cluster scoped resources for those subjects do not get deleted. This happens due to an incomplete authorization logic check. A user who is a member of an affected group with authenticated access to Rancher could use this to access resources they should no longer have access to. The exposure level will depend on the original permission level gra

O3 Security · Impact-Aware SCA

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Find it across Go, including transitive dependencies.

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CVSS Score

8.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

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

CWE Classification

CWE-284CWE-284

Weaponization

No Nuclei template, Metasploit module or public proof-of-concept found.

OpenSSF Scorecard

Package health score

rancher

6.8/10

Code-Review10/10

Maintained10/10

Branch-Protection5/10

Assessed Nov 2, 2026

Timeline

Disclosed

Apr 4, 2022

Last updated

Oct 24, 2026

Identifiers

CVE-2021-36775

GHSA-28g7-896h-695v

GO-2024-2760

References

Advisorynvd.nist.gov · CVE 2021 36775 Reportbugzilla.suse.com · show bug.cgi Webgithub.com · GHSA 28g7 896h 695v Packagegithub.com · rancher

Related vulnerabilities

This CVE is high severity; 8 of 8 other CVEs affecting rancher are rated as high or higher (top: critical).

CVE-2026-41053CVE-2026-44939CVE-2026-41052CVE-2026-25705CVE-2022-31247CVE-2021-36783CVE-2021-25320GHSA-hwm2-4ph6-w6m5

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-36775 — rancher

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Impact

Patches

Workarounds

References

For more information

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-36775 in your dependencies?