CVE-2026-44659 PUBLISHED

Zen Browser Mac - Address Bar Spoofing via Long Subdomain

Assigner: GitHub_M
Reserved: 07.05.2026 Published: 11.05.2026 Updated: 11.05.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CVSS Score: 4.7

Product Status

Vendor zen-browser
Product desktop
Versions
  • Version < 1.19.12b is affected

References

Problem Types

  • CWE-451: User Interface (UI) Misrepresentation of Critical Information CWE