VULNERABILITY INTELLIGENCE
CVE-2026-71555
CVSS score4.1 MEDIUM
EPSS probability0.29%
CISA KEVNot currently listed
Published2026-08-06
Last modified2026-10-24
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N
Description
PILOS (Platform for Interactive Live-Online Seminars) is a frontend for BigBlueButton. From 2.1.0 until 4.14.1, PILOS does not send a Cross-Origin-Opener-Policy response header, so pages opened by PILOS via a link that opens a new browsing context (e.g., target="_blank") retain a window.opener reference back to the originating PILOS tab. A malicious destination page reached this way can use window.opener to navigate or manipulate the original PILOS tab, a technique known as reverse tabnabbing, potentially redirecting an authenticated user to a phishing page that mimics PILOS. This issue is fixed in version 4.14.1.
Weakness classification
- CWE-1022: Use of Web Link to Untrusted Target with window.opener Access