CVE-2026-71555 MEDIUM

CVE-2026-71555: PILOS: Reverse tabnabbing in room description

Vendor Thm-Health
Product PILOS
Weakness CWE-1022
Published August 6, 2026
Last update August 6, 2026
View on NVD All CVEs

CVSS base score

4.1/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 6, 2026 CVE published