medium6.5
CVE-2026-53524
WeeChat (Wee Enhanced Environment for Chat) is a free chat client.
Impact
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.
Affected products
| Product | Affected versions |
|---|---|
| Versions 4.3.0 | through 4.9.0 |
Versions were read from the advisory text. No structured product data has been published for this record yet.