CVE-2026-71555

PILOS: Reverse tabnabbing in room description

MEDIUM
4.1
CVSS Score
Published: August 6, 2026 at 09:51 PM UTC
Updated: October 24, 2026 at 03:10 PM UTC
1 product affected across 1 vendorPILOS

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Severity
MEDIUM4.1
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

>= 2.1.0, < 4.14.1
Affected range stops below 4.14.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.1MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-1022

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