CVE-2026-44659

MEDIUM

Zen Browser Mac - Address Bar Spoofing via Long Subdomain

Title source: cna
STIX 2.1

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.

References (1)

Core 1
Core References

Scores

CVSS v3 4.7
EPSS 0.0016
EPSS Percentile 6.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-451
Status published
Products (1)
zen-browser/desktop < 1.19.12b
Published May 11, 2026
Tracked Since May 11, 2026