Forem is open source software for building communities. Prior to commit a2ab6d4, a maliciously crafted email address could allow an attacker to bypass domain allowlist or denylist restrictions and gain access to invite-only forem deployments. The issue is patched as of `a2ab6d4`. As a workaround, some SMTP servers and email delivery providers may drop or refuse to send maliciously crafted email addresses.
Severity
CVSS 3.1
8.2 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS
0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-31)