WeeChat 4.3.0/4.9.0 Relay relay_websocket_inflate resource consumption

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.75

Summaryinfo

A vulnerability was found in WeeChat 4.3.0/4.9.0. It has been rated as problematic. Affected is the function relay_websocket_inflate of the component Relay Module. This manipulation causes resource consumption. This vulnerability is handled as CVE-2026-53524. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in WeeChat 4.3.0/4.9.0. It has been declared as problematic. Affected by this vulnerability is the function relay_websocket_inflate of the component Relay Module. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-53524 since 06/09/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 4.9.1 eliminates this vulnerability.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Resource consumption
CWE: CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: WeeChat 4.9.1

Timelineinfo

06/09/2026 CVE reserved
08/21/2026 +73 days VulDB entry created
08/22/2026 +0 days Advisory disclosed
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-53524 (🔒)
GCVE (CVE): GCVE-0-2026-53524
GCVE (VulDB): GCVE-100-394261

Entryinfo

Created: 08/22/2026 00:33
Changes: 08/22/2026 00:33 (65)
Complete: 🔍
Cache ID: 216::103

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