VULNERABILITY INTELLIGENCE
CVE-2026-41431
CVSS score8 HIGH
EPSS probability0.20%
CISA KEVNot currently listed
Published2026-05-11
Last modified2026-10-26
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Description
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.
Weakness classification
- CWE-347: Improper Verification of Cryptographic Signature