How severe is CVE-2021-39133?

CVE-2021-39133 has a CVSS score of 6.8/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-39133?

CVE-2021-39133 affects the following packages: org.rundeck:rundeck-core (Maven), org.rundeck:rundeck-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2021-39133?

Update org.rundeck:rundeck-core to 3.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39133 is resolved across your whole dependency graph.

How do I detect CVE-2021-39133 in my Maven dependencies?

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

How do I mitigate CVE-2021-39133 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-2021-39133 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-39133 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-2021-39133?

CVE-2021-39133 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 37th 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-2021-39133?

CVE-2021-39133 is classified as Cross-Site Request Forgery (CSRF) (CWE-352). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-39133 published, and has it been updated?

CVE-2021-39133 was published on August 30, 2021 and was last updated on July 9, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven

Not in CISA KEV

MEDIUM severity

CVE-2021-39133 — rundeck-core

MEDIUMFix: rundeck/rundeck@67c4eed

CVE-2021-39133 is a medium-severity (CVSS 6.8) Cross-Site Request Forgery (CSRF) vulnerability in org.rundeck:rundeck-core. A fix is available for org.rundeck:rundeck-core — see the affected versions and patch details below.

Cross-Site Request Forgery (CSRF) can run untrusted code on Rundeck server

Also known asGHSA-3jmw-c69h-426c

Published

Aug 30, 2021

Updated

Jul 9, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

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

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs37th percentile — riskier than 37% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2021-39133 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

☕org.rundeck:rundeck-core☕org.rundeck:rundeck-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Impact

A user with admin access to the system resource type is potentially vulnerable to a CSRF attack that could cause the server to run untrusted code on all Rundeck editions.

Patches

Available in Rundeck 3.4.3 and 3.3.14

Workarounds

Please visit https://rundeck.com/security for information about specific workarounds.

For more information

If you have any questions or comments about this advisory:

Email us at [email protected]

To report security issues to Rundeck please use the form at https://rundeck.com/security

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`org.rundeck:rundeck-core`	≥ 3.4.0&&< 3.4.3	3.4.3`org.rundeck:rundeck-core:3.4.3`
☕Maven	`org.rundeck:rundeck-core`	all versions	3.3.14`org.rundeck:rundeck-core:3.3.14`

Affected Products

1 product · 2 configurations

Application

rundeckpagerduty

≥ 3.4.0 && < 3.4.3

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.rundeck:rundeck-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.rundeck:rundeck-core to 3.4.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39133 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

### Impact A user with `admin` access to the `system` resource type is potentially vulnerable to a CSRF attack that could cause the server to run untrusted code on all Rundeck editions. ### Patches Available in Rundeck 3.4.3 and 3.3.14 ### Workarounds Please visit [https://rundeck.com/security](https://rundeck.com/security) for information about specific workarounds. ### For more information If you have any questions or comments about this advisory: * Email us at [[email protected]](mailto:[email protected]) To report security issues to Rundeck please use the form at [https://rund