CVE-2026-53525

HIGH CVSS 3.1: 7.4 EPSS 0.25%
Updated Sep 10, 2026
Weechat
Parameter Value
CVSS 7.4 (HIGH)
Affected Versions 0.3.1 — 4.9.0
Type CWE-208
Vendor Weechat
Public PoC No

WeeChat (Wee Enhanced Environment for Chat) is a free chat client. In versions 0.3.1 through 4.9.0, the WeeChat relay authentication uses non-constant-time string comparison functions (weechat_strcasecmp and strcmp) to verify password hashes and plaintext passwords. An attacker can exploit timing differences to extract the server-computed hash character by character, then authenticate using the correct hash without knowing the password.

Version 4.9.1 fixes the issue.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products

weechat:weechat

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