CVE-2026-53524
WeeChat has a Decompression Bomb in Relay WebSocket (DoS)
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.
INFO
Published Date :
Aug. 21, 2026, 11:16 p.m.
Last Modified :
Sept. 9, 2026, 9:06 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | MITRE-CVE |
Solution
- Update WeeChat to version 4.9.1 or later.
- Ensure relay module is configured securely.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-53524.
| URL | Resource |
|---|---|
| https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3 | |
| https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53524 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-53524
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-53524 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53524 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 24, 2026
Action Type Old Value New Value Added Reference https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3 Added SSVC {'id': 'CVE-2026-53524', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-24T20:09:05.967952Z'} -
New CVE Received by [email protected]
Aug. 21, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'weechat', 'product': 'weechat', 'versions': [{'status': 'affected', 'version': '>= 4.3.0, < 4.9.1'}]}] Added 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. Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-409 Added Reference https://github.com/weechat/weechat/security/advisories/GHSA-v2v4-45wm-5cr3