The from method in library/core/class.email.php in Vanilla Forums before 2.3.1 allows remote attackers to spoof the email domain in sent messages and potentially obtain sensitive information via a crafted HTTP Host header, as demonstrated by a password reset request.
Severity
CVSS 3.0
7.5 high
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
84% chance of exploitation in the next 30 days; higher than 99% of CVEs (scores of 2026-10-31)