CVE intelligence and bounded remediation
CVE-2025-66622 — matrix-sdk-base is the base component to build a Matrix client library
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.
- Severity
- High
- CVSS
- 7.5 (3.1)
- Published
- 2025-12-09
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-755
Affected products
- matrix / matrix-rust-sdk
Matched remediation archetype
General vulnerability remediation
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
- Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
- Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.
Remediate safely
- Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
- Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
- Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.