How severe is CVE-2021-25313?

CVE-2021-25313 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-25313?

CVE-2021-25313 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-2021-25313?

Update github.com/rancher/rancher to 2.5.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25313 is resolved across your whole dependency graph.

How do I detect CVE-2021-25313 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-2021-25313 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2021-25313 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-25313 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-2021-25313?

CVE-2021-25313 has an EPSS (Exploit Prediction Scoring System) score of 1.5%, placing it in the 74th 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-2021-25313?

CVE-2021-25313 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-25313 published, and has it been updated?

CVE-2021-25313 was published on March 5, 2021 and was last updated on October 20, 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

MEDIUM severity

CVE-2021-25313 — rancher

MEDIUM

CVE-2021-25313 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in github.com/rancher/rancher. A fix is available for github.com/rancher/rancher — see the affected versions and patch details below.

Rancher Cross-site Scripting Vulnerability

Also known asGHSA-6m8r-jh89-rq7h

Published

Mar 5, 2021

Updated

Oct 20, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs74th percentile — riskier than 74% 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

A Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Rancher allows remote attackers to execute JavaScript via malicious links. This issue affects: SUSE Rancher Rancher versions prior to 2.5.6.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/rancher/rancher`	≥ 2.5.0&&< 2.5.6	2.5.6`go get github.com/rancher/rancher@v2.5.6`
🐹Go	`github.com/rancher/rancher`	≥ 2.4.0&&< 2.4.14	2.4.14`go get github.com/rancher/rancher@v2.4.14`
🐹Go	`github.com/rancher/rancher`	all versions	2.3.11`go get github.com/rancher/rancher@v2.3.11`

Affected Products

1 product · 1 configurations

Application

ranchersuse

< 2.5.6

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 2.5.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-25313 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2021-25313 in your dependencies?

Find it across Go, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

6.1/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Raw vector

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

CWE Classification

CWE-79Cross-site Scripting (XSS)

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

Mar 5, 2021

Last updated

Oct 20, 2026

Identifiers

CVE-2021-25313

GHSA-6m8r-jh89-rq7h

References

Advisorygithub.com · v2.5.6 Advisorynvd.nist.gov · CVE 2021 25313 Reportbugzilla.suse.com · show bug.cgi Reportgithub.com Webgithub.com · v2.3.11 Webgithub.com · v2.4.14

Related vulnerabilities

This CVE is medium 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 20, 2026