---
id: CVE-2024-52815
aliases:
  - GHSA-f3r3-h2mq-hx2h
  - PYSEC-2026-1611
title: Synapse allows a a malformed invite to break the invitee's `/sync`
summary: Synapse allows a a malformed invite to break the invitee's `/sync`
severity: high
vendor: matrix-synapse
product: matrix-synapse
ecosystem: pip
affected:
  - matrix-synapse < 1.120.1
patched:
  - matrix-synapse 1.120.1
published: '2024-12-03'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-f3r3-h2mq-hx2h'
references:
  - url: >-
      https://github.com/element-hq/synapse/security/advisories/GHSA-f3r3-h2mq-hx2h
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2024-52815'
  - url: 'https://github.com/element-hq/synapse'
tags:
  - osv
  - pip
epss: 0.0057
epssPercentile: 0.45973
ingestedAt: '2026-07-08T18:25:48.630Z'
---

## Overview

### Impact

Synapse versions before 1.120.1 fail to properly validate invites received over federation. This vulnerability allows a malicious server to send a specially crafted invite that disrupts the invited user's `/sync` functionality.

### Patches

Synapse 1.120.1 rejects such invalid invites received over federation and restores the ability to sync for affected users.

### Workarounds

Server administrators can disable federation from untrusted servers.

### For more information

If you have any questions or comments about this advisory, please email us at [security at element.io](mailto:security@element.io).


## Affected packages

- `matrix-synapse < 1.120.1`

## Remediation

Upgrade to a patched release:

- `matrix-synapse 1.120.1`