No exploitation reported

CVE-2021-21604

No exploitation reported by the sources we read.

Published2021-01-13
WeaknessCWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier allows attackers with permission to create or configure various objects to inject crafted content into Old Data Monitor that results in the instantiation of potentially unsafe objects once discarded by an administrator.

Timeline

dates in UTC

2021-01-1316:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-21604?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-21604?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Jenkins

Branch	Affected	Fixed in	Source
2.263	≤ 2.263.1	no fix published	NVD
2.274	≤ 2.274	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

www.jenkins.ioVendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVSS 3.18read 2026-10-23
NVDCVSS 2.06read 2026-10-23
NVDweakness (CWE)CWE-502read 2026-10-23
FIRST EPSSEPSS score1.7 %2026-10-22

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
Published: 2021-01-13
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-21604?

Is CVE-2021-21604 actively exploited?

Active exploitation of CVE-2021-21604 has not been confirmed. Its EPSS score was 1.7% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-21604?

CVE-2021-21604 has a CVSS v3 base score of 8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H.

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