CVE-2026-66390 Apache Software Foundation CVE debrief

Who should care

Users of Apache Wicket versions from 9.0.0 through 9.23.0 and 10.0.0 through 10.9.0 should be aware of this vulnerability and take steps to upgrade to a fixed version. This includes operators, administrators, and security teams responsible for maintaining and securing systems that utilize Apache Wicket.

Technical summary

The CVE-2026-66390 vulnerability is a Cross-site Scripting (XSS) issue in Apache Wicket. This type of vulnerability occurs when user input is not properly sanitized, allowing an attacker to inject malicious code into web pages. In this case, the vulnerability affects Apache Wicket versions from 9.0.0 through 9.23.0 and 10.0.0 through 10.9.0. The CVSS score for this vulnerability is 6.1, indicating a medium severity level. Users are recommended to upgrade to version 10.10.0, which fixes the issue.

Defensive priority

Medium priority should be given to upgrading Apache Wicket to version 10.10.0 or later to address this vulnerability. This involves reviewing and updating affected systems, monitoring for potential exploitation attempts, and ensuring that compensating controls are in place for exposed systems.

Recommended defensive actions

• Upgrade Apache Wicket to version 10.10.0 or later
• Review and update affected systems
• Monitor for potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-27T17:16:41.643Z and was last modified on 2026-07-27T20:26:26.840Z. The NVD entry is currently Awaiting Analysis. This information is based on the provided source corpus and may not reflect the current status. Users should verify the information with the official sources for the most up-to-date details.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.