What’s Vulnerable › Vulnerabilities

CVE-2021-21687

• Severity: critical (CVSS 9.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-11-04 · updated 2026-06-17
• Weakness: CWE-862

Description

Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create symbolic links when unarchiving a symbolic link in FilePath#untar.

Affected products

• Jenkins: before 2.303.3; before 2.319 — fixed in 2.303.3, 2.319

How to fix

Upgrade to a fixed version: Jenkins 2.303.3, 2.319. Check the vendor advisory for mitigations.

References

• https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455
• https://www.jenkins.io/security/advisory/2021-11-04/#SECURITY-2455

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