# CVE-2022-39252: matrix-sdk-crypto contains potential impersonation via room key forward responses

> Attackers can impersonate users by inserting invalid room keys because the SDK fails to verify the source of forwarded keys.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Sep 2022
- **Updated:** 23 Apr 2025
- **Also known as:** GHSA-vp68-2wrm-69qm, RUSTSEC-2022-0085

## What is CVE-2022-39252?

CVE-2022-39252 is a high-severity authentication bypass vulnerability in matrix-org matrix-rust-sdk, published on 29 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-322 (Key Exchange without Entity Authentication), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2022-39252?

3 open source packages ship an affected version, including matrix-sdk-crypto. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `matrix-sdk-crypto` | crates.io | All versions | 0.6.0 |
| `matrix-sdk-crypto` | crates.io | All versions | 0.6.0 |
| `matrix-sdk-crypto` | crates.io | From 0.0.0-0 | 0.6.0 |

Products: Matrix Matrix-Rust-Sdk.

## How do I fix CVE-2022-39252?

Upgrade matrix-sdk-crypto to 0.6.0 or later.

## Is CVE-2022-39252 being exploited?

There is no known exploitation of CVE-2022-39252 in the wild and no public exploit code.

## Other vulnerabilities in matrix-org matrix-rust-sdk

- [CVE-2025-66622](https://insights.sbomify.com/CVE-2025-66622/): matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values (low 1.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-39252 and fix it if it is affected.

What it is: CVE-2022-39252 is a high-severity authentication bypass vulnerability in matrix-org matrix-rust-sdk, published on 29 Sep 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2022-39252 in the wild and no public exploit code.

Affected packages and fixed versions:
- matrix-sdk-crypto (crates.io): affected all versions; fixed in 0.6.0
- matrix-sdk-crypto (crates.io): affected all versions; fixed in 0.6.0
- matrix-sdk-crypto (crates.io): affected from 0.0.0-0; fixed in 0.6.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2022-39252/ (Markdown: https://insights.sbomify.com/CVE-2022-39252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-39252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-39252
- OSV: https://osv.dev/vulnerability/CVE-2022-39252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-39252/
Summaries are generated and may contain mistakes; the official description above is the record.