Improper beacon events in matrix-js-sdk can result in availability issues

Exploitation

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

CVSS

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

EPSS

• CVE-2022-39236: 1.36% estimated exploitation activity in the next 30 days; percentile 71.77 (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 Improperly formed beacon events (from MSC3488) can disrupt or impede the matrix-js-sdk from functioning properly, potentially impacting the consumer's ability to process data safely. Note that the matrix-js-sdk can appear to be operating normally but be excluding or corrupting runtime data presented to the consumer. Patches This is patched in matrix-js-sdk v19.7.0 Workarounds Redacting applicable events, waiting for the sync processor to store data, and restarting the client can often fix it. Alternatively, redacting the applicable events and clearing all storage will fix the further perceived issues. Downgrading to an unaffected version, noting that such a version may be subject to other vulnerabilities, will additionally resolve the issue. References N/A - This was a logic error in the SDK. For more information If you have any questions or comments about this advisory please email us at security at matrix.org.

Published by the source

29 Sep 2022, 14:36 UTC

Last modified by the source

8 Nov 2023, 04:10 UTC

Source last checked

26 Oct 2026, 12:17 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hvv8-5v86-r45x

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hvv8-5v86-r45x

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# Patch Next advisory brief: CVE-2022-39236

Advisory: Improper beacon events in matrix-js-sdk can result in availability issues
IDs: CVE-2022-39236, GHSA-hvv8-5v86-r45x
Record: https://patchnext.com/advisories/cve-2022-39236 (revision 2, source checked 26 Oct 2026, 12:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: matrix-js-sdk 19.7.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm matrix-js-sdk: affected >= 17.1.0-rc.1, < 19.7.0; fixed in 19.7.0

## Suggested inspection (read-only)
- `npm ls matrix-js-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-js-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-hvv8-5v86-r45x (OSV record GHSA-hvv8-5v86-r45x lists affected ranges: npm matrix-js-sdk >=17.1.0-rc.1 <19.7.0 (fixed))
- Verified: https://github.com/advisories/GHSA-hvv8-5v86-r45x (GitHub-reviewed advisory GHSA-hvv8-5v86-r45x lists affected ranges: npm matrix-js-sdk >=17.1.0-rc.1 <19.7.0)

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