GitHub Advisoryadvisory · crates.io
GHSA-jj6p-3m75-g2p3 matrix-sdk-base denial of service via custom m.room.join_rules event values
LOW
Official page ↗
- Aliases
- CVE-2025-66622
- Ecosystem
- crates.io
- Packages
- matrix-sdk-base
- Severity
- Low
- CVSS vector
- 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
- Weaknesses
- CWE-755
- Reviewed
- 2025-12-08
Affected packages
• crates.io matrix-sdk-base: < 0.16.0 → fixed in 0.16.0
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.
Related
Alias · CVE (1)
- CVE-2025-66622 matrix-sdk-base is the base component to build a Matrix client library. vulnerability
Weakness · CWE (1)
- CWE-755 Improper Handling of Exceptional Conditions weakness
References
- https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3 web
- https://nvd.nist.gov/vuln/detail/CVE-2025-66622 advisory
- https://github.com/matrix-org/matrix-rust-sdk/pull/5924 web
- https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0 web
- https://github.com/matrix-org/matrix-rust-sdk package
- https://rustsec.org/advisories/RUSTSEC-2025-0135.html web