Vulnerability in Matrix-Org Matrix-Rust-Sdk

CVE-2025-48937

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust. matrix-sdk-crypto since version 0.8.0 and up to 0.11.0 does not correctly validate the sender of an encrypted event. Accordingly, a malicious homeserver operator can modify events served to clients, making those events appear to the recipient as if they were sent by another user. This vulnerability is fixed in 0.11.1 and 0.12.0.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-48937: held from 0.003 to 0.004.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-48937?
CVE-2025-48937 is a medium-severity vulnerability in Matrix-Org Matrix-Rust-Sdk, classified under Authentication Bypass by Spoofing. CVSS score: 4.9/10. Published 2025-06-10.
How severe is CVE-2025-48937?
Medium severity. CVSS v3 base score is 4.9 out of 10.