What is CVE-2026-42509?

CVE-2026-42509 is a medium-severity vulnerability in Apache Wicket, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-05-06.

How severe is CVE-2026-42509?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Apache Wicket

CVE-2026-42509

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Apache Wicket. This issue affects Apache Wicket: from 8.0.0 through 8.17.0, 9.0.0, from 10.0.0 through 10.8.0. Users are recommended to upgrade to version 10.9.0, which fixes the issue.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-05-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (46.5th percentile), scored 2026-10-22.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Apache Wicket
Apache Software Foundation Wicket — versions 8.0.0, 9.0.0, 10.0.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

lists.apache.org/thread/52nrq4tt07gxz4r6sj5gyocz5s6bprjp (vendor-advisory, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2026-42509?: CVE-2026-42509 is a medium-severity vulnerability in Apache Wicket, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-05-06.
How severe is CVE-2026-42509?: Medium severity. CVSS v3 base score is 6.1 out of 10.