QID 981367

QID 981367: Python (pip) Security Update for matrix-synapse (GHSA-5wrh-4jwv-5w78)

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.

Requests to user provided domains were not restricted to external IP addresses when transitional IPv6 addresses were used. Outbound requests to federation, identity servers, when calculating the key validity for third-party invite events, sending push notifications, and generating URL previews are affected. This could cause Synapse to make requests to internal infrastructure on dual-stack networks.

  • CVSS V3 rated as High - 6.3 severity.
  • CVSS V2 rated as Medium - 4.9 severity.
  • Solution
    This issue is fixed by #9240.Workaround:
    Outbound requests to the following address ranges can be blocked by a firewall, if unused for internal communication between systems:

    * `::ffff/80`
    * `::0000/80` (note that this IP range is considered deprecated by the IETF)
    * `2002::/16` (note that this IP range is considered deprecated by the IETF)
    Vendor References

    CVEs related to QID 981367

    Software Advisories
    Advisory ID Software Component Link
    GHSA-5wrh-4jwv-5w78 matrix-synapse URL Logo github.com/advisories/GHSA-5wrh-4jwv-5w78

    © 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