CVE-2026-45150

Zen Browser - Missing Fullscreen Security Notification Allows Origin Spoofing

MEDIUM

6.3

CVSS Score

Published: July 15, 2026 at 03:35 PM UTC

Updated: October 24, 2026 at 09:10 PM UTC

1 product affected across 1 vendorZen Browser (desktop)

Using desktop by zen-browser?

Get instant alerts when new vulnerabilities affect desktop - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

MEDIUM6.3

Exploit prediction

EPSS 0.3%

SSVC

PoC

Description

Zen is a firefox-based browser. Prior to 1.19.13b, Zen Browser did not provide a persistent, clearly visible security notification when a webpage entered fullscreen mode, allowing an attacker-controlled page to hide the real browser UI and origin information, imitate a trusted website UI, and combine with long-domain URL eliding to spoof a trusted origin for phishing and credential theft. This issue is fixed in version 1.19.13b.

Affected

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

Zen Browser (desktop)· Zen Browser

90%

v < 1.19.13b

Affected range stops below 1.19.13b, 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.

References (1)

x_refsource_CONFIRM

Source: cverecord

https://github.com/zen-browser/desktop/security/advisories/GHSA-vjfv-85qf-v25c

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

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

CVSS

6.3MEDIUMGitHub_M

Vector?

Quick Info

StatusDEFERRED

CWE

CWE-451

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create account Sign in

Free plan, no card