matrix-sdk-base is vulnerable to DoS via custom m.room.join_rules event values

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2025-66622
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2025-12-09 16:18:21 UTC
Updated2026-10-07 20:10:01 UTC
Descriptionmatrix-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.

Risk And Classification

Primary CVSS: v4.0 1.3 LOW from [email protected]

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.004130000 probability, percentile 0.334950000 (date 2026-10-07)

Problem Types: CWE-755 | CWE-755 CWE-755: Improper Handling of Exceptional Conditions

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary1.3LOWCVSS: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/C...
4.0CNADECLARED1.3LOWCVSS: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
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
Passive
Confidentiality
None
Integrity
None
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Matrix Matrix-rust-sdk All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Matrix-org Matrix-rust-sdk affected < 0.16.0 Not specified

References

ReferenceSourceLinkTags
github.com/matrix-org/matrix-rust-sdk/security/advisories/GHSA-jj6p-3m75... [email protected] github.com Patch, Vendor Advisory
rustsec.org/advisories/RUSTSEC-2025-0135.html [email protected] rustsec.org Third Party Advisory
github.com/matrix-org/matrix-rust-sdk/commit/4ea0418abefab2aa93f8851a4d3... [email protected] github.com Patch
github.com/matrix-org/matrix-rust-sdk/pull/5924 [email protected] github.com Issue Tracking, Patch
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