What is CVE-2026-84673?

CVE-2026-84673 is a high-severity vulnerability in Jenkins Project Customizable Header Plugin, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2026-09-02.

How severe is CVE-2026-84673?

High severity. CVSS v3 base score is 8.8 out of 10.

XSS in Jenkins Project Customizable Header Plugin

CVE-2026-84673

Jenkins Customizable Header Plugin 295.v2544b_ca_19b_97 and earlier allows overwriting the plugin's appearance configuration through Stapler data binding, allowing attackers to configure a custom SVG icon containing inline JavaScript, resulting in a stored cross-site scripting (XSS) vulnerability.

Vulnerability class: XSS (Cross-Site Scripting)

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Jenkins Project Customizable Header Plugin

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

jenkinsci-cert@googlegroups.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-84673?: CVE-2026-84673 is a high-severity vulnerability in Jenkins Project Customizable Header Plugin, classified under Cross-site Scripting. CVSS score: 8.8/10. Published 2026-09-02.
How severe is CVE-2026-84673?: High severity. CVSS v3 base score is 8.8 out of 10.