CVE-2026-45056
Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution
- State
- Published
- Severity
- 6.9 Medium
- Published
- Sep 11, 2026
- Updated
- Sep 14, 2026
- Reserved
- May 8, 2026
Description
matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. Starting in version 0.12.0 and prior to version 0.17.0, the matrix-sdk-crypto crate was missing a check for the user ID when decrypting an Olm-encrypted event containing the `sender_device_keys` property. This could be exploited to forge an encrypted to-device event, but only if the attacker colludes with the homeserver operator. This issue is fixed in matrix-sdk-crypto 0.17.0. There are no known workarounds for the issue.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.9 Medium | 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 | GitHub_M |
Weaknesses
- CWE-290 Authentication Bypass by Spoofing
Affected Products
| Product | Versions |
|---|---|
matrix-rust-sdkmatrix-org |
|
References
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