SB2026090841 - Authentication bypass using an alternate path or channel in WeeChat

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Main Vulnerability Database SB2026090841

SB2026090841 - Authentication bypass using an alternate path or channel in WeeChat

Published: September 8, 2026

Security Bulletin ID SB2026090841
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Authentication bypass using an alternate path or channel (CVE-ID: CVE-2026-86036)

CWE-ID: CWE-288 - Authentication Bypass Using an Alternate Path or Channel

CVSSv4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to gain an authenticated relay session without knowing the relay password.

The vulnerability exists due to improper authentication in the relay_auth_password_hash() function when processing hash authentication submissions that specify the plain password hash algorithm. A remote attacker can submit crafted authentication data specifying the plain algorithm to gain an authenticated relay session without knowing the relay password.

Exploitation requires a reachable api or weechat relay listener with a password configured and the default password-hash algorithm allow-list.


Remediation

Install update from vendor's website.

References