CVE-2026-44658
Zen Browser: RSS Live-Folder Item URLs Are Not Scheme-Restricted Before Trusted Tab Creation
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Zen Browser: RSS Live-Folder Item URLs Are Not Scheme-Restricted Before Trusted Tab Creation
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.
- Record
CVE-2026-44658- CVSS 3.1
- 2.4 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2026-29132
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.
- Record
EUVD-2026-29132- CVSS 3.1
- 2.4 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-44658- CVSS 3.1
- 2.4 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
Zen Browser: RSS Live-Folder Item URLs Are Not Scheme-Restricted Before Trusted Tab Creation
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.
- Record
CVE-2026-44658- CVSS 3.1
- 2.4 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:L/A:N - Weakness
- CWE-20
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-44658 is a low vulnerability (CVSS 2.4) in Zen-browser Desktop, published May 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.16%, the 4th percentile. No source names a fixed version.