# CVE-2026-53524: weechat: WeeChat (Wee Enhanced Environment for Chat) is a free chat client

CVE-2026-53524 is fixed in weechat on 1 platform, first by DEBIAN-CVE-2026-53524, released August 18, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-53524
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0048
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 20, 2026

## Description

WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 4.3.0 through 4.9.0, the WeeChat relay module's WebSocket permessage-deflate decompression function relay_websocket_inflate() has no upper bound on output size. An authenticated relay user can send a small compressed WebSocket frame (~100 bytes) that decompresses to gigabytes, exhausting all server memory and crashing the entire WeeChat process. The api protocol enables permessage-deflate and requires authentication before WebSocket upgrade. Version 4.9.1 patches the issue.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | weechat Debian 14 | 4.9.3-1 | [DEBIAN-CVE-2026-53524](https://patchblox.com/security/data/fix/linux/debian-cve-2026-53524.md) | Aug 18, 2026 |
| Linux | weechat opensuse-leap 16.0 | 4.10.0-bp160.1.1 | [OPENSUSE-SU-2026:21615-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21615-1.md) | Aug 20, 2026 |

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Data as of 2026-11-08T13:06:02Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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