CVE-2025-66622
matrix-sdk-base is the base component to build a Matrix client library. Versions 0.14.1 and prior are 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. This is fixed in version 0.16.0.
Published:Dec 9, 2025
Last Modified:Mar 17, 2026
EPS:Dec 9, 2025
EPSS Score:0.00063
CVSS Score:7.5
Affected Products
Vendor
Product
Action
Vendor
Matrix
Product
Matrix-rust-sdk
Matrix
Matrix-rust-sdk
Vendor
Matrix-org
Product
Matrix-rust-sdk
Matrix-org
Matrix-rust-sdk
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
No CAPEC recorded yet
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
