What is CVE-2021-21658?

CVE-2021-21658 is a critical-severity vulnerability in Jenkins Nuget. CVSS score: 9.1/10. Published 2021-05-25.

How severe is CVE-2021-21658?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Jenkins Nuget

CVE-2021-21658

Jenkins Nuget Plugin 1.0 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.

Published 2021-05-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.015 (74.0th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.015 · newest: 0.015 · change: 0.000

Affected products

Jenkins Nuget
Jenkins Project Nuget Plugin — versions unspecified

References

www.jenkins.io/security/advisory/2021-05-25/ (Vendor Advisory)
www.openwall.com/lists/oss-security/2021/05/25/3 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2021-21658?: CVE-2021-21658 is a critical-severity vulnerability in Jenkins Nuget. CVSS score: 9.1/10. Published 2021-05-25.
How severe is CVE-2021-21658?: Critical severity. CVSS v3 base score is 9.1 out of 10.