matrix-rust-sdk is an implementation of a Matrix client-server library in Rust. Versions of the matrix-sdk-crypto Rust crate before 0.8.0 lack a dedicated mechanism to notify that a user's cryptographic identity has changed from a verified to an unverified one, which could cause client applications relying on the SDK to overlook such changes. matrix-sdk-crypto 0.8.0 adds a new VerificationLevel::VerificationViolation enum variant which indicates that a previously verified identity has been changed.

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust. The `UserIdentity::is_verified()` method in the matrix-sdk-crypto crate before version 0.7.2 doesn't take into account the verification status of the user's own identity while performing the check and may as a result return a value contrary to what is implied by its name and documentation. If the method is used to decide whether to perform sensitive operations towards a user identity, a malicious homeserver could manipulate the outcome in order to make the identity appear trusted. This is not a typical usage of the method, which lowers the impact. The method itself is not used inside the `matrix-sdk-crypto` crate. The 0.7.2 release of the `matrix-sdk-crypto` crate includes a fix. All users are advised to upgrade. There are no known workarounds for this vulnerability.

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust, and matrix-sdk-crypto is the Matrix encryption library. Prior to version 0.6, when a user requests a room key from their devices, the software correctly remembers the request. When the user receives a forwarded room key, the software accepts it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.6 fixes this issue.