PYSEC-2026-846
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/matrix-synapse/PYSEC-2026-846.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-846
- Aliases
- Published
- 2026-07-06T08:03:24.087354Z
- Modified
- 2026-07-07T11:46:05.957211927Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
- Summary
- Matrix Synapse DoS
- Details
-
Matrix Synapse before 0.28.1 is prone to a denial of service flaw where malicious events injected with depth = 2<sup>63</sup> - 1 render rooms unusable, related to
federation/federation_base.pyandhandlers/message.py, as exploited in the wild in April 2018. - References
-
- https://nvd.nist.gov/vuln/detail/CVE-2018-10657
- https://github.com/matrix-org/synapse/commit/33f469ba19586bbafa0cf2c7d7c35463bdab87eb
- https://docs.google.com/document/d/1I3fi2S-XnpO45qrpCsowZv8P8dHcNZ4fsBsbOW7KABI/edit#heading=h.fj95ykuss7s1
- https://github.com/matrix-org/synapse
- https://matrix.org/blog/2018/05/01/security-update-synapse-0-28-1
- https://pypi.org/project/matrix-synapse
- https://github.com/advisories/GHSA-vmcc-4p4x-x7wg
Affected packages
PyPI / matrix-synapse
Package
- Name
- matrix-synapse
- View open source insights on deps.dev
- Purl
- pkg:pypi/matrix-synapse