CVE-2025-66622
HIGHmatrix-sdk-base < 0.16.0 - Denial of Service via Custom m.room.join_rules Serialization
Title source: llmDescription
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.
References (4)
Core 4
Core References
Vendor Advisory x_refsource_confirm
https://github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75-g2p3
Issue Tracking x_refsource_misc
https://github.com/matrix-org/matrix-rust-sdk/pull/5924
Patch x_refsource_misc
https://github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d39c723e703e6b0
Various Sources x_refsource_misc
https://rustsec.org/advisories/RUSTSEC-2025-0135.html
Scores
CVSS v3
7.5
EPSS
0.0034
EPSS Percentile
26.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-755
Status
published
Products (3)
crates.io/matrix-sdk-base
0 - 0.16.0crates.io
matrix/matrix-rust-sdk
< 0.16.0
matrix-org/matrix-rust-sdk
< 0.16.0
Published
Dec 09, 2025
Tracked Since
Feb 18, 2026