What is CVE-2021-21678?

CVE-2021-21678 is a high-severity vulnerability in Jenkins Saml, classified under Cross-Site Request Forgery (CSRF). CVSS score: 8.8/10. Published 2021-08-31.

How severe is CVE-2021-21678?

High severity. CVSS v3 base score is 8.8 out of 10.

CSRF in Jenkins Saml

CVE-2021-21678

Jenkins SAML Plugin 2.0.7 and earlier allows attackers to craft URLs that would bypass the CSRF protection of any target URL in Jenkins.

Vulnerability class: CSRF (Cross-Site Request Forgery)

Published 2021-08-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Jenkins Saml
Jenkins Project Saml Plugin — versions 1.1.3, unspecified, 1.1.8

Weakness classification (CWE)

CWE-352 — Cross-Site Request Forgery (CSRF)

References

www.jenkins.io/security/advisory/2021-08-31/ (Vendor Advisory)
www.openwall.com/lists/oss-security/2021/08/31/1 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-21678?: CVE-2021-21678 is a high-severity vulnerability in Jenkins Saml, classified under Cross-Site Request Forgery (CSRF). CVSS score: 8.8/10. Published 2021-08-31.
How severe is CVE-2021-21678?: High severity. CVSS v3 base score is 8.8 out of 10.