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CVE-2026-45150mediumCWE-451

Zen Browser - Missing Fullscreen Security Notification Allows Origin Spoofing

13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.3epss 0.3%
exploitation probability
0.3%top 83% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Affected products
zen-browser · desktop