CVE-2021-23976

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 is a different issue from CVE-2020-26954 and only affected Firefox for Android. Other operating systems are unaffected. This vulnerability affects Firefox < 86.

• CWE-1021

• https://bugzilla.mozilla.org/show_bug.cgi?id=1684627Issue Tracking, Permissions Required, Vendor Advisory
• https://security.gentoo.org/glsa/202104-10Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=1684627Issue Tracking, Permissions Required, Vendor Advisory
• https://security.gentoo.org/glsa/202104-10Third Party Advisory
• https://www.mozilla.org/security/advisories/mfsa2021-07/Release Notes, Vendor Advisory

Published

Feb 26, 2021

Last Modified

Jun 17, 2026

Status

Modified

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