What is CVE-2022-39252?

CVE-2022-39252 is a high-severity vulnerability in Matrix Matrix-Rust-Sdk, classified under Improper Authentication. CVSS score: 8.6/10. Published 2022-09-29.

How severe is CVE-2022-39252?

High severity. CVSS v3 base score is 8.6 out of 10.

Is CVE-2022-39252 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Matrix Matrix-Rust-Sdk

CVE-2022-39252

matrix-rust-sdk is an implementation of a Matrix client-server library in Rust, and matrix-sdk-crypto is the Matrix encryption library. Prior to version 0.6, when a user requests a room key from their devices, the software correctly remembers the request. When the user receives a forwarded room key, the software accepts it without checking who the room key came from. This allows homeservers to try to insert room keys of questionable validity, potentially mounting an impersonation attack. Version 0.6 fixes this issue.

Vulnerability class: Broken Authentication

Published 2022-09-29 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.006 (47.4th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 47.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.006 · change: +0.001

Affected products

Matrix Matrix-Rust-Sdk
Matrix-Org Matrix-Rust-Sdk — versions < 0.6

Weakness classification (CWE)

Public proof-of-concept exploits

ARPSyndicate/cvemon

References

github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-vp68-2wrm-69qm (Third Party Advisory)
github.com/matrix-org/matrix-rust-sdk/commit/093fb5d0aa21c0b5eaea6ec96b477f1075… (Patch, Third Party Advisory)
github.com/matrix-org/matrix-rust-sdk/commit/41449d2cc360e347f5d4e1c154ec1e3185… (Patch, Third Party Advisory)
github.com/matrix-org/matrix-rust-sdk/releases/tag/matrix-sdk-0.6.0 (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2022-39252?: CVE-2022-39252 is a high-severity vulnerability in Matrix Matrix-Rust-Sdk, classified under Improper Authentication. CVSS score: 8.6/10. Published 2022-09-29.
How severe is CVE-2022-39252?: High severity. CVSS v3 base score is 8.6 out of 10.
Is CVE-2022-39252 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.