CVE-2020-26954: Mozilla Firefox Mobile

Medium severity, CVSS 4.3. EPSS: 0.6% chance of exploitation in the next 30 days.

When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed declaring webapp manifests for other origins. This could be used to gain fullscreen access for UI spoofing and could also lead to cross-origin attacks on targeted websites. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

Affected products

• Mozilla Firefox Mobile: before 83.0 (fixed in 83.0)

Published 2020-12-09. Last modified 2026-08-19.