# CVE-2022-39254: python-matrix-nio: matrix-nio is a Python Matrix client library, designed according to sans I/O principles

CVE-2022-39254 is fixed in python-matrix-nio on 1 platform, first by DEBIAN-CVE-2022-39254, released September 29, 2022. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2022-39254
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0068
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 29, 2022

## Description

matrix-nio is a Python Matrix client library, designed according to sans I/O principles. Prior to version 0.20, when a users requests a room key from their devices, the software correctly remember the request. Once they receive a forwarded room key, they accept 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 0.20 fixes the issue.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | python-matrix-nio Debian 12.15 (bookworm) | 0.20.0-1 | [DEBIAN-CVE-2022-39254](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39254.md) | Sep 29, 2022 |
| Linux | python-matrix-nio Debian 13.5 (trixie) | 0.20.0-1 | [DEBIAN-CVE-2022-39254](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39254.md) | Sep 29, 2022 |
| Linux | python-matrix-nio Debian 14 | 0.20.0-1 | [DEBIAN-CVE-2022-39254](https://patchblox.com/security/data/fix/linux/debian-cve-2022-39254.md) | Sep 29, 2022 |

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