matrix-sdk-ui provides GUI-centric utilities on top of matrix-rust-sdk. The message edit validation logic in the `matrix-sdk-ui` crate prior to 0.17.0 is missing a check: when replacing an encrypted event, the replacement event itself is not required to be encrypted. This enables a malicious homeserver administrators (or actors with equivalent power) to impersonate or spoof messages as if they were sent by a victim user. `matrix-sdk-ui` 0.17.0 fixes the message edit validation logic to align with the algorithm for replacement events[^1] described in the Matrix specification.
No known workarounds are available.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
References 4
https://github.com/matrix-org/matrix-rust-sdk/pull/6454
security-advisories@github.com
https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1
security-advisories@github.com
https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-h97m-27f…
security-advisories@github.com
https://rustsec.org/advisories/RUSTSEC-2026-0158.html
security-advisories@github.com