Home/CVE/Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not escape notification bar response contents, resulting in a cr
CVE

CVE-2021-21603

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not escape notification bar response contents, resulting in a cr

Jenkins 2.274 and earlier, LTS 2.263.1 and earlier does not escape notification bar response contents, resulting in a cross-site scripting (XSS) vulnerability.

MEDIUM · CVSS 5.4 EPSS 0.00319
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
▤

Affected Products & Versions

2
jenkins<= 2.263.1
jenkins<= 2.274
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
Maven org.jenkins-ci.main:jenkins-core MODERATE fixed in 2.275
▣

Scoring & Timeline

5.4
MEDIUM · CVSS v3.1 · jenkinsci-cert@googlegroups.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD13 Jan 2021 · 04:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
⚑

Vendor Advisories

3
rhsaRHSA-2021:0423Moderate
rhsaRHSA-2021:0429Moderate
rhsaRHSA-2021:0637Important
🔗

References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-1889Vendor Advisory
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