matrix-org/matrix-rust-sdk · Security
Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution
- GHSA ID
- GHSA-wfq4-36m3-9g42
- CVE ID
- CVE-2026-45056
- Severity
- medium
- Published
- Updated
- CVSS v4
- 6.9 · CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Description
Impact
The matrix-sdk-crypto crate before 0.16.1 is missing a check for the sender's user ID when decrypting an Olm-encrypted to-device message containing the sender_device_keys property.
This could be exploited to spoof the sender of an encrypted to-device message, but only if the attacker colludes with (or is) the homeserver operator.
Patches
This issue is fixed in matrix-sdk-crypto 0.16.1.
Workarounds
There are no known workarounds for the issue.
References
This issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/6553.
For more information
If you have any questions or comments about this advisory, please email us at security at matrix.org.
CWEs
- CWE-290 · Authentication Bypass by Spoofing
References
- https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-wfq4-36m3-9g42 ↗
- https://github.com/matrix-org/matrix-rust-sdk/pull/6553 ↗
- https://github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.16.1 ↗
- https://rustsec.org/advisories/RUSTSEC-2026-0159.html ↗
- https://github.com/advisories/GHSA-wfq4-36m3-9g42 ↗