# CVE-2023-32683: matrix-synapse: Synapse is a Matrix protocol homeserver written in Python with the Twisted framework

CVE-2023-32683 is fixed in matrix-synapse on 1 platform, first by DEBIAN-CVE-2023-32683, released June 6, 2023. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2023-32683
- Priority: Routine
- CVSS: 5.4 (medium)
- EPSS: 0.0061
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 6, 2023

## Description

Synapse is a Matrix protocol homeserver written in Python with the Twisted framework. A discovered oEmbed or image URL can bypass the `url_preview_url_blacklist` setting potentially allowing server side request forgery or bypassing network policies. Impact is limited to IP addresses allowed by the `url_preview_ip_range_blacklist` setting (by default this only allows public IPs) and by the limited information returned to the client: 1. For discovered oEmbed URLs, any non-JSON response or a JSON response which includes non-oEmbed information is discarded. 2. For discovered image URLs, any non-image response is discarded. Systems which have URL preview disabled (via the `url_preview_enabled` setting) or have not configured a `url_preview_url_blacklist` are not affected. This issue has been addressed in version 1.85.0. Users are advised to upgrade. User unable to upgrade may also disable URL previews.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | matrix-synapse Debian 14 | 1.90.0-1 | [DEBIAN-CVE-2023-32683](https://patchblox.com/security/data/fix/linux/debian-cve-2023-32683.md) | Jun 6, 2023 |
| Linux | matrix-synapse Ubuntu 18.04.6 LTS (bionic) | 0.24.0+dfsg-1ubuntu0.1~esm4 | [matrix-synapse 0.24.0+dfsg-1ubuntu0.1~esm4](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-matrix-synapse-0.24.0-dfsg-1ubuntu0.1-esm4.md) | Oct 31, 2023 |
| Linux | matrix-synapse Ubuntu 20.04 LTS (focal) | 1.11.0-1ubuntu0.1~esm2 | [matrix-synapse 1.11.0-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-matrix-synapse-1.11.0-1ubuntu0.1-esm2.md) | Oct 31, 2023 |
| Linux | matrix-synapse Ubuntu 22.04.1 LTS (jammy) | 1.53.0-1ubuntu0.1~esm2 | [matrix-synapse 1.53.0-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-matrix-synapse-1.53.0-1ubuntu0.1-esm2.md) | Dec 3, 2024 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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