QID 981369

QID 981369: Python (pip) Security Update for matrix-synapse (GHSA-246w-56m2-5899)

Security update has been released for matrix-synapse to fix the vulnerability.

Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

The password reset endpoint served via Synapse was vulnerable to cross-site scripting (XSS) attacks. The impact depends on the configuration of the domain that Synapse is deployed on, but may allow access to cookies and other browser data, CSRF vulnerabilities, and access to other resources served on the same domain or parent domains.

  • CVSS V3 rated as Critical - 8.2 severity.
  • CVSS V2 rated as Medium - 4.3 severity.
  • Solution
    This is fixed in #9200.Workaround:
    Depending on the needs and configuration of the homeserver a few options are available:

    1. Password resets can be disabled by delegating email to a third-party service (via the `account_threepid_delegates.email` setting) or disabling email (by not configuring the `email` setting).

    2. If the homeserver is not configured to use passwords (via the `password_config.enabled` setting) then the affected endpoint can be blocked at a reverse proxy:

    * `/_synapse/client/password_reset/email/submit_token`

    3. The `password_reset_confirmation.html` template can be overridden with a custom template that manually escapes the variables using [JInja2's `escape` filter](https://jinja.palletsprojects.com/en/2.11.x/templates/#escape). See the `email.template_dir` setting.
    Vendor References

    CVEs related to QID 981369

    Software Advisories
    Advisory ID Software Component Link
    GHSA-246w-56m2-5899 matrix-synapse URL Logo github.com/advisories/GHSA-246w-56m2-5899

    © CVE.report 2026

    Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

    CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

    Free CVE JSON API cve.report/api

    CVE.report and Source URL Uptime Status status.cve.report