CVE-2026-44659
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).
Does this matter?
Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 4.7 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
- EPSS
- 0.16% probability · 6th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-451
- Source
- security-advisories@github.com
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.