Quick answers
- Is CVE-2026-16435 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-16435 being exploited in the wild.
- How severe is CVE-2026-16435?
- Medium severity, with a CVSS score of 5.9, published 14 September 2026.
- Which products and versions are affected?
- IBM WebSphere Application Server 8.5, 9.0 (prior to 8.5.5.31 and 9.0.5.29 respectively).
- Is there a fix for CVE-2026-16435?
- 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-2026-16435 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-16435?
- Check whether you run IBM WebSphere Application Server 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 an authentication bypass affecting IBM WebSphere Application Server versions 9.0 and 8.5 when XD or Intelligent-Management features are enabled. The root cause lies in improper handling of HTTP permission methods and trusting HTTP method-based authorization decisions, allowing an attacker to bypass authentication checks. No prior authentication is required to exploit this vulnerability; an attacker can craft specially crafted network requests to bypass the authentication mechanism. Successful exploitation grants unauthorized access to protected administrative functions and sensitive data with high confidentiality impact. IBM recommends upgrading to patched versions 9.0.5.29 or 8.5.5.31 and later.
Affected products
- IBM WebSphere Application Server 8.5, 9.0 (prior to 8.5.5.31 and 9.0.5.29 respectively)
Timeline
- 2026-09-14: disclosed