Matrix Javascript SDK is the Matrix Client-Server SDK for JavaScript. Starting with version 17.1.0-rc.1, improperly formed beacon events 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. This is patched in matrix-js-sdk v19.7.0. Redacting applicable events, waiting for the sync processor to store data, and restarting the client are possible workarounds. 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.