CVE-2021-21687

Name: CVE-2021-21687
Creator: NVD / NIST
Published: 2021-11-04T17:15:08.39+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.1/10EPSS 1.34%

Last modified Jun 17, 2026

CVE-2021-21687 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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.. EPSS estimates a 1.34% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

9.1/10

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

EPSS Probability

1.34%

67.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Jenkins	Jenkins	< 2.303.3
Jenkins	Jenkins	< 2.319

References

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

Timeline

Published: Nov 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21687?

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.

How severe is CVE-2021-21687?

CVE-2021-21687 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 1.34% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21687?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21687?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST