CVE-2022-39254

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.

Scoring

Severity
HIGH
CVSS base score
8.6
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
EPSS probability
0.23%
CWE
CWE-322, CWE-287
Published
2022-09-29
Last modified
2026-03-13

Affected products

Weakness type

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