The m_authenticate function in modules/m_sasl.c in Charybdis before 3.5.3 allows remote attackers to spoof certificate fingerprints and consequently log in as another user via a crafted AUTHENTICATE parameter.
Severity
CVSS 3.0
8.1 high
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
1.1% chance of exploitation in the next 30 days; higher than 64% of CVEs (scores of 2026-10-31)