Zen Browser - Missing Fullscreen Security Notification Allows Origin Spoofing
Priority HIGH 67CWE-451Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Active
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Spoofing
- Confidentiality · integrity · availability
- None · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-451.
Summary
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00314 24th percentileScored 2026-11-07
Fix Fixed desktop (zen-browser): 1.19.13b
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| zen-browser | desktop | before 1.19.13b | 1.19.13b | Patch available | CNA |
- desktop Vendorzen-browser Affected before 1.19.13b Fixed in 1.19.13b Patch available CNA
Remediation
- Fix · CNA desktop (zen-browser) Fixed in 1.19.13b
Timeline
- 2026-10-02 Threatist record created from CVE-2026-45150
More zen-browser vulnerabilities
- TI-2026-30030 Zen Browser MAR updater ships with signature verification removed — unsigned updates accepted CVSS 3.1HIGH 8.0
- TI-2026-32559 Zen Browser Mac - Address Bar Spoofing via Long Subdomain CVSS 3.1MEDIUM 4.7
- TI-2026-32558 Zen Browser: RSS Live-Folder Item URLs Are Not Scheme-Restricted Before Trusted Tab Creation CVSS 3.1LOW 2.4
- TI-2026-41404 Zen: Context-menu "Open link in glance" / "Split link in new tab" loads a page-controlled… CVSS 3.1N/A 0.0
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences