CVE-2026-41431Zen is a firefox-based browser.
Updated under an hour ago ()
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Zen is a firefox-based browser. Prior to 1.19.9b, Zen Browser ships a Mozilla Application Resource (MAR) updater (org.mozilla.updater) that has had all MAR signature verification stripped from the Firefox codebase it was forked from. The MAR files served to users contain zero cryptographic signatures, and the updater binary contains zero cryptographic verification code. This eliminates the defense-in-depth that MAR signing provides. If the update server or GitHub release pipeline is compromised, arbitrary unsigned code can be delivered to all Zen users via the auto-update mechanism. This vulnerability is fixed in 1.19.9b.
- CVSS
- 8.0 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-347
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Deferred
- Record last updated
- Jun 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
No affected products are listed yet.
References
- https://github.com/zen-browser/desktop/commit/270db6d6713d2c6c14d9df0b4bc7662843d3d54e
- https://github.com/zen-browser/desktop/security/advisories/GHSA-qpj9-m8jc-mw6q
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.