How severe is CVE-2021-21678?

CVE-2021-21678 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-21678 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-21678?

CVE-2021-21678 affects Jenkins Saml. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-21678?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-21678 published?

CVE-2021-21678 was published on 2021-08-31 and last updated on 2026-06-17.

CVE-2021-21678

CVE-2021-21678 is a high-severity vulnerability in Jenkins Saml with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-352.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 6.8
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-352
Affected product: Jenkins Saml
Published: 2021-08-31
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2021-21678?: CVE-2021-21678 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-21678 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-21678?: CVE-2021-21678 affects Jenkins Saml. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-21678?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-21678 published?: CVE-2021-21678 was published on 2021-08-31 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:jenkins:saml:*:*:*:*:*:jenkins:*:*

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