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TI-2026-32558 Aliases CVE-2026-44658

Zen Browser: RSS Live-Folder Item URLs Are Not Scheme-Restricted Before Trusted Tab Creation

Priority LOW 12CWE-20Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
Required
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

Zen is a firefox-based browser. Prior to 1.19.12b, RSS feed URLs entered by the user are validated to http: or https: in promptForFeedUrl, but item links inside the feed are not subject to the same restriction. The provider maps each RSS/Atom item link into item.url, filters only for presence and date, and returns the item list. The live-folder manager later creates pinned lazy tabs from these values with gBrowser.addTrustedTab(item.url, ...). This vulnerability is fixed in 1.19.12b.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00157 4th percentileScored 2026-11-07
Fix Fixed desktop (zen-browser): 1.19.12b

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
zen-browserdesktopbefore 1.19.12b1.19.12bPatch availableCNA
  • desktop Vendorzen-browser Affected before 1.19.12b Fixed in 1.19.12b Patch available CNA

Remediation

  • Fix · CNA desktop (zen-browser) Fixed in 1.19.12b

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-44658

References

Other 1

  • TI-2026-30030 Zen Browser MAR updater ships with signature verification removed — unsigned updates accepted CVSS 3.1HIGH 8.0
  • TI-2026-32978 Zen Browser - Missing Fullscreen Security Notification Allows Origin Spoofing CVSS 4.0MEDIUM 6.3
  • TI-2026-32559 Zen Browser Mac - Address Bar Spoofing via Long Subdomain CVSS 3.1MEDIUM 4.7
  • 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