CVE-2024-42369Network attack vector

Client hang via cyclic room predecessor traversal

Published Aug 20, 2024 · Updated Sep 3, 2024

Uncontrolled recursion in matrix-js-sdk before 34.3.1 allows remote attackers to hang clients through cyclic room predecessor chains. The findPredecessorRooms traversal follows predecessor identifiers without tracking visited rooms, so getRoomUpgradeHistory never terminates when a cycle returns to a seen room. An attacker-controlled homeserver must supply the cyclic structure, and the client must inspect upgrade history or leave the room; the bounded consequence is a client hang.

CVSS severity4.1
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Uncontrolled recursion in matrix-js-sdk before 34.3.1 allows remote attackers to hang clients through cyclic room predecessor chains. The findPredecessorRooms traversal follows predecessor identifiers without tracking visited rooms, so getRoomUpgradeHistory never terminates when a cycle returns to a seen room. An attacker-controlled homeserver must supply the cyclic structure, and the client must inspect upgrade history or leave the room; the bounded consequence is a client hang.

The record

CVE
CVE-2024-42369
Published
Aug 20, 2024
Updated
Sep 3, 2024
Vendor
The Matrix.org Foundation
Product
matrix-js-sdk
Classifications
CWE-674, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 20, 2024CVE publishedPublication date reported by the CVE source.
  2. Sep 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 34.3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Matrix.org Foundation · matrix-js-sdkversion=< 34.3.1

Published CVSS scores

4.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:N/A:L
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-674Uncontrolled Recursion
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo