CVE-2023-32323

unknown
Published 2023-05-24 · Modified 2023-11-08
CVSS v3
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L
CVSS v2
VIR risk

Description

Synapse is an open-source Matrix homeserver written and maintained by the Matrix.org Foundation. A malicious user on a Synapse homeserver X with permission to create certain state events can disable outbound federation from X to an arbitrary homeserver Y. Synapse instances with federation disabled are not affected. In versions of Synapse up to and including 1.73, Synapse did not limit the size of `invite_room_state`, meaning that it was possible to create an arbitrarily large invite event. Synapse 1.74 refuses to create oversized `invite_room_state` fields. Server operators should upgrade to Synapse 1.74 or newer urgently.

Predictions

Exploit likelihood
30%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2023-32323

OS impact

OSVersionStatusFixed in
debian debianforkyfixed1.74.0-1
debian debiansidfixed1.74.0-1

Package impact

EcosystemPackageVulnerableFixed
python PyPImatrix-synapse<1.74.01.74.0

References

Verify integrity in audit chain (admin only). AS-IS.