# CVE-2026-66391: Apache Wicket protection mechanism failure via weak randomness

Source: https://junglewise.ai/threats/cve-2026-66391-apache-wicket-protection-mechanism-failure-via-weak-randomness  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-27. Updated: 2026-07-27  
License: CC BY 4.0 with a link back

CVE-2026-66391 · Severity: info · Published 2026-07-27

Apache Wicket, a popular Java web application framework, contains a vulnerability where it uses insufficiently random values for security-sensitive operations. This could allow an attacker to bypass certain protection mechanisms, potentially leading to unauthorized access or session hijacking. Organizations using affected versions should upgrade to version 10.10.0 to ensure their web applications remain secure.

Technologies: [Apache Software Foundation Wicket](https://junglewise.ai/threats/technologies/wicket). Vendors: [Apache Software Foundation](https://junglewise.ai/threats/vendors/apache-software-foundation).

## Quick answers

**Is CVE-2026-66391 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-66391 being exploited in the wild.

**How severe is CVE-2026-66391?** Informational severity, published 27 July 2026.

**Which products and versions are affected?** Apache Software Foundation Wicket 9.0.0 through 9.23.0, 10.0.0 through 10.9.0.

**Is there a fix for CVE-2026-66391?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-66391 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-66391?** Check whether you run Apache Software Foundation Wicket at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is classified under CWE-330 (Use of Insufficiently Random Values) and CWE-693 (Protection Mechanism Failure) within the Apache Wicket framework. The root cause is the generation of predictable or weak random values used in security contexts, which undermines the effectiveness of built-in protection mechanisms. While specific exploitation details are not provided in the advisory, such flaws typically allow for session prediction, CSRF token bypass, or other cryptographic attacks. The issue is resolved in Apache Wicket version 10.10.0.

## Affected products

- Apache Wicket 9.0.0 through 9.23.0, 10.0.0 through 10.9.0

## Timeline

- 2026-07-27: advisory: NVD published the CVE record based on Apache Software Foundation data.
- 2026-07-27: disclosed

## References

- [https://lists.apache.org/thread/hfzcgjsbmmthzchtb8b8nv47d95scmqk](https://lists.apache.org/thread/hfzcgjsbmmthzchtb8b8nv47d95scmqk)

## Related threats

- [Apache Wicket path traversal in FolderUploadsFileManager](https://junglewise.ai/threats/cve-2026-43975-apache-wicket-path-traversal-in-folderuploadsfilemanager)
- [Apache Wicket information disclosure in PackageResourceGuard](https://junglewise.ai/threats/cve-2026-43646-apache-wicket-information-disclosure-in-packageresourceguard)
- [Apache Wicket Cross-site Scripting in web page generation](https://junglewise.ai/threats/cve-2026-42509-apache-wicket-cross-site-scripting-in-web-page-generation)
- [Apache Wicket session fixation in AuthenticatedWebSession](https://junglewise.ai/threats/cve-2026-40010-apache-wicket-session-fixation-in-authenticatedwebsession)