CVE-2026-44658: CWE-20: Improper Input Validation in zen-browser desktop
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.
AI Analysis
Technical Summary
Zen-browser, a Firefox-based desktop browser, had an input validation flaw in versions before 1.19.12b. While user-entered RSS feed URLs were validated to ensure they used http or https schemes, the individual item links within the RSS/Atom feeds were not subjected to the same validation. These item links were mapped into item.url and used by the live-folder manager to create pinned lazy tabs via gBrowser.addTrustedTab(item.url, ...), potentially allowing unvalidated URLs to be treated as trusted. This improper input validation is classified under CWE-20. The issue was addressed and fixed in version 1.19.12b.
Potential Impact
The vulnerability has a low CVSS score of 2.4 and does not impact confidentiality or availability, only integrity to a limited extent. It requires high privileges and user interaction to exploit. There are no known exploits in the wild. The impact is limited to the possibility of untrusted URLs being added as trusted tabs, which could potentially lead to minor integrity issues within the browser environment.
Mitigation Recommendations
This vulnerability is fixed in zen-browser version 1.19.12b. Users and administrators should upgrade to version 1.19.12b or later to remediate this issue. Since no official remediation level is provided beyond the fix, applying the update is the recommended action. No additional mitigation steps are indicated.
CVE-2026-44658: CWE-20: Improper Input Validation in zen-browser desktop
Description
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.
CVSS v3.1
Score 2.4low
Affected software
pkg:github/zen-browser/desktopRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Zen-browser, a Firefox-based desktop browser, had an input validation flaw in versions before 1.19.12b. While user-entered RSS feed URLs were validated to ensure they used http or https schemes, the individual item links within the RSS/Atom feeds were not subjected to the same validation. These item links were mapped into item.url and used by the live-folder manager to create pinned lazy tabs via gBrowser.addTrustedTab(item.url, ...), potentially allowing unvalidated URLs to be treated as trusted. This improper input validation is classified under CWE-20. The issue was addressed and fixed in version 1.19.12b.
Potential Impact
The vulnerability has a low CVSS score of 2.4 and does not impact confidentiality or availability, only integrity to a limited extent. It requires high privileges and user interaction to exploit. There are no known exploits in the wild. The impact is limited to the possibility of untrusted URLs being added as trusted tabs, which could potentially lead to minor integrity issues within the browser environment.
Mitigation Recommendations
This vulnerability is fixed in zen-browser version 1.19.12b. Users and administrators should upgrade to version 1.19.12b or later to remediate this issue. Since no official remediation level is provided beyond the fix, applying the update is the recommended action. No additional mitigation steps are indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-07T16:20:08.659Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a021045cbff5d86103d46c2
Added to database: 05/11/2026, 17:22:13 UTC
Last enriched: 05/11/2026, 17:37:25 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 99
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