CVE-2026-42509
MEDIUMImproper 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,…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
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.
Affected Products
wicketapacheDetection & mitigation playbook
Vendor / applianceDetect
Inventory every apache wicket deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the apache wicket security patch or hotfix for CVE-2026-42509 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-42509 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-42509. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-42509 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-42509 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.