CVE-2026-44659

Zen Browser Mac - Address Bar Spoofing via Long Subdomain

MEDIUM
4.7
CVSS Score
Published: May 11, 2026 at 05:01 PM UTC
Updated: October 26, 2026 at 06:10 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
Severity
MEDIUM4.7
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Zen is a firefox-based browser. Prior to 1.19.12b, the ZEN Browser incorrectly truncates long hostnames in the address bar and shows only the attacker-controlled prefix of the subdomain, hiding the actual registrable domain (eTLD+1). As a result, an attacker can craft extremely long malicious subdomains that visually imitate trusted brands, and the browser will display only the spoofed prefix, misleading users about the actual origin of the site. This directly compromises the URL bar as a security indicator and creates a phishing/supply-chain attack vector. This vulnerability is fixed in 1.19.12b.

Affected

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

v < 1.19.12b
Affected range stops below 1.19.12b, 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

4.7MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
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.

Free plan, no card