GitHub Advisoryadvisory · crates.io

GHSA-wfq4-36m3-9g42 Matrix Rust SDK: Sender-binding gaps in to-device and room-key attribution

MEDIUM Published 2026-06-04 Modified 2026-06-04 Official page ↗
Aliases
CVE-2026-45056
Ecosystem
crates.io
Packages
matrix-sdk-crypto
Severity
Moderate
CVSS vector
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
Weaknesses
CWE-290
Reviewed
2026-06-04

Affected packages

• crates.io matrix-sdk-crypto: >= 0.12.0, < 0.16.1 → fixed in 0.16.1

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.

Related

Alias · CVE (1)

  • CVE-2026-45056 matrix-sdk-crypto is a no-network-IO implementation of a state machine that handles end-to-end encryption for Matrix clients. vulnerability

Weakness · CWE (1)

  • CWE-290 Authentication Bypass by Spoofing weakness

References