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Vulnerability record · CVE-2021-21696 · published 4 November 2021

CVE-2021-21696: Jenkins vulnerability

Jenkins · Jenkins

Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted library with a modified variant. This results in unsandboxed code execution in the Jenkins controller process.

9.8 CVSS 3.1 Critical EPSS 2.4% · top 16.3%
9.8CVSS 3.1 base score, v2 7.5
2.4%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs, allowing attackers in control of agent processes to replace the code of a trusted library with a modified variant. This results in unsandboxed code execution in the Jenkins controller process.

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

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://www.openwall.com/lists/oss-security/2021/11/04/3 Mailing ListThird Party Advisory
https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423 MitigationVendor Advisory
http://www.openwall.com/lists/oss-security/2021/11/04/3 Mailing ListThird Party Advisory
https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2423 MitigationVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-21696), CISA KEV, FIRST EPSS (scores of 2026-10-14). This page is refreshed as NVD updates the record.