The application failed to account for exceptions thrown by the `loadManifestFromFile` method during add-on signature verification. This flaw, triggered by an invalid or unsupported extension manifest, could have caused runtime errors that disrupted the signature validation process. As a result, the enforcement of signature validation for unrelated add-ons may have been bypassed.  Signature validation in this context is used to ensure that third-party applications on the user's computer have not tampered with the user's extensions, limiting the impact of this issue. This vulnerability affects Firefox < 133, Firefox ESR < 128.5, Thunderbird < 133, and Thunderbird < 128.5.

https://bugzilla.mozilla.org/show_bug.cgi?id=1929600

https://www.mozilla.org/security/advisories/mfsa2024-63/

https://www.mozilla.org/security/advisories/mfsa2024-64/

https://www.mozilla.org/security/advisories/mfsa2024-67/

https://www.mozilla.org/security/advisories/mfsa2024-68/