GHSA-jj6p-3m75-g2p3

The matrix-sdk-base crate is unable to handle responses that include custom m.room.join_rules values due to a serialization bug. This can be exploited to cause a denial-of-service condition, if a user is invited to a room with non-standard join rules, the crate's sync process will stall, preventing further processing for all rooms. ### Patches The issue is fixed in matrix-sdk-base 0.16.0. ### Workarounds Users can leave affected rooms on another client to mitigate the issue. ### References The issue was fixed in https://github.com/matrix-org/matrix-rust-sdk/pull/5924.