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)

Published · last modified .

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.

EPSS exploit prediction

EPSS: 0.005 (42.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-84673: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

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.