Quick answers
- Is CVE-2026-87901 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-87901 being exploited in the wild.
- How severe is CVE-2026-87901?
- High severity, with a CVSS score of 8.3, published 23 October 2026.
- Which products and versions are affected?
- phpBB phpBB.
- Is there a fix for CVE-2026-87901?
- 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-2026-87901 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-87901?
- Check whether you run Phpbb. 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 a reflected XSS in phpBB's registration module caused by improper input sanitization. An attacker can inject malicious JavaScript through registration parameters that is reflected back to the user's browser without proper encoding. This requires user interaction (clicking a malicious link) but no authentication, and allows theft of session tokens or account takeover.
Affected products
- phpBB phpBB
Timeline
- 2026-10-23: disclosed