matrix-org/matrix-rust-sdk · Security

matrix-sdk-base denial of service via custom m.room.join_rules event values

GHSA ID
GHSA-jj6p-3m75-g2p3
CVE ID
CVE-2025-66622
Severity
low
Published
Updated
CVSS v4
1.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U

Description

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.

CWEs

References