Matrix.org wrote the following
post Fri, 23 Sep 2022 15:52:28 +0200
Pre-disclosure: we are planning a coordinated security release of multiple Matrix clients starting 16:00 UTC Wed Sep 28th to address some critical issues. We have no evidence of these being exploited in the wild, but please get ready to upgrade on Wed!
https://matrix.org/blog/2022/09/23/pre-disclosure-upcoming-critical-security-release-of-matrix-sd-ks-and-clients