CVE-2026-71555
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
48/100
Published: 2026-08-06
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
Low
UI:
Required
S:
Changed
C:
None
I:
Low
A:
None
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.