Vulnerability · Published Sep 11, 2026 · Assigned by GitHub_M
CVE-2026-45057matrix-sdk-ui: Incomplete edit validation
Medium 4.9
In plain English
A medium-severity insufficient verification of data authenticity in matrix-sdk-ui from matrix-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| matrix-org | matrix-sdk-ui | < 0.16.1 |
Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-h97m-27fx-42rx x_refsource_CONFIRM
- https://github.com/matrix-org/matrix-rust-sdk/pull/6454 x_refsource_MISC
- https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1 x_refsource_MISC
- https://rustsec.org/advisories/RUSTSEC-2026-0158.html x_refsource_MISC