Matrix SDK for React's URL preview setting for a room is controllable by the homeserver

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/U:Red · score source

EPSS

• CVE-2024-42347: 0.43% estimated exploitation activity in the next 30 days; percentile 37.04 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact A malicious homeserver could manipulate a user's account data to cause the client to enable URL previews in end-to-end encrypted rooms, in which case any URLs in encrypted messages would be sent to the server. Even if the CVSS score would be 4.1 (AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N) the maintainer classifies this as High severity issue. Patches This was patched in matrix-react-sdk 3.105.1. Workarounds Deployments that trust their homeservers, as well as closed federations of trusted servers, are not affected. References N/A.

Published by the source

6 Aug 2024, 14:12 UTC

Last modified by the source

8 Aug 2024, 16:38 UTC

Source last checked

26 Oct 2026, 12:31 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-f83w-wqhc-cfp4

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-f83w-wqhc-cfp4

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# Patch Next advisory brief: CVE-2024-42347

Advisory: Matrix SDK for React's URL preview setting for a room is controllable by the homeserver
IDs: CVE-2024-42347, GHSA-f83w-wqhc-cfp4
Record: https://patchnext.com/advisories/cve-2024-42347 (revision 3, source checked 26 Oct 2026, 12:31 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: matrix-react-sdk 3.105.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm matrix-react-sdk: affected < 3.105.1; fixed in 3.105.1

## Suggested inspection (read-only)
- `npm ls matrix-react-sdk --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on matrix-react-sdk.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-f83w-wqhc-cfp4 (OSV record GHSA-f83w-wqhc-cfp4 lists affected ranges: npm matrix-react-sdk >=0 <3.105.1 (fixed))
- Verified: https://github.com/advisories/GHSA-f83w-wqhc-cfp4 (GitHub-reviewed advisory GHSA-f83w-wqhc-cfp4 lists affected ranges: npm matrix-react-sdk >=0 <3.105.1)

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