What’s Vulnerable › Vulnerabilities

CVE-2021-21603

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-01-13 · updated 2026-06-17
• Weakness: CWE-79

Description

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.

Affected products

• Jenkins: through 2.263.1; through 2.274

References

• https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-1889
• https://www.jenkins.io/security/advisory/2021-01-13/#SECURITY-1889

Get alerted when CVE-2021-21603 or the next vulnerability affects your stack