How severe is CVE-2021-25318?

CVE-2021-25318 has a CVSS score of 8.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-25318?

CVE-2021-25318 affects the following packages: github.com/rancher/rancher (Go), github.com/rancher/rancher (Go). Ecosystems affected: Go.

How do I fix CVE-2021-25318?

Update github.com/rancher/rancher to 2.4.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25318 is resolved across your whole dependency graph.

How do I detect CVE-2021-25318 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-2021-25318 if there is no patch (or I can't update yet)?

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.

Is CVE-2021-25318 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-25318 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-2021-25318?

CVE-2021-25318 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 64th 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-2021-25318?

CVE-2021-25318 is classified as CWE-732 (CWE-732). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-25318 published, and has it been updated?

CVE-2021-25318 was published on July 15, 2021 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-2021-25318 — rancher

HIGH

CVE-2021-25318 is a high-severity (CVSS 8.8) CWE-732 vulnerability in github.com/rancher/rancher. A fix is available for github.com/rancher/rancher — see the affected versions and patch details below.

Rancher does not properly specify ApiGroup when creating Kubernetes RBAC resources

Also known asGHSA-f9xf-jq4j-vqw4GO-2024-2768

Published

Jul 15, 2021

Updated

Oct 24, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs64th percentile — riskier than 64% 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

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

Downstream clusters: apiservices clusters clusterrepos persistentvolumes storageclasses

Rancher management cluster apprevisions apps catalogtemplates catalogtemplateversions clusteralertgroups clusteralertrules clustercatalogs clusterloggings clustermonitorgraphs clusterregistrationtokens clusterroletemplatebindings clusterscans etcdbackups nodepools nodes notifiers pipelineexecutions pipelines pipelinesettings podsecuritypolicytemplateprojectbindings projectalertgroups projectalertrules projectcatalogs projectloggings projectmonitorgraphs projectroletemplatebindings projects secrets sourcecodeproviderconfigs

There is not a direct mitigation besides upgrading to the patched Rancher versions.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/rancher/rancher`	≥ 2.0.0&&< 2.4.16	2.4.16`go get github.com/rancher/rancher@v2.4.16`
🐹Go	`github.com/rancher/rancher`	≥ 2.5.0&&< 2.5.9	2.5.9`go get github.com/rancher/rancher@v2.5.9`

Affected Products

1 product · 2 configurations

Application

rancherrancher

≥ 2.5.0 && < 2.5.9

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 2.4.16 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25318 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.

Frequently Asked Questions

A vulnerability was discovered in Rancher versions 2.0 through the aforementioned fixed versions, where users were granted access to resources regardless of the resource's API group. For example Rancher should have allowed users access to `apps.catalog.cattle.io`, but instead incorrectly gave access to `apps.*`. Resource affected include: **Downstream clusters:** apiservices clusters clusterrepos persistentvolumes storageclasses **Rancher management cluster** apprevisions apps catalogtemplates catalogtemplateversions clusteralertgroups clusteralertrules clustercatalogs clusterloggings clust

O3 Security · Impact-Aware SCA

Is CVE-2021-25318 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

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-732CWE-732

Weaponization

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

OpenSSF Scorecard

Package health score

rancher

6.7/10

Maintained10/10

Code-Review10/10

Branch-Protection5/10

Assessed Oct 26, 2026

Timeline

Disclosed

Jul 15, 2021

Last updated

Oct 24, 2026

Identifiers

CVE-2021-25318

GHSA-f9xf-jq4j-vqw4

GO-2024-2768

References

Advisorynvd.nist.gov · CVE 2021 25318 Reportbugzilla.suse.com · show bug.cgi Webgithub.com Webpkg.go.dev · GO 2024 2768 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-2021-25318 — rancher

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-25318 in your dependencies?