CVE-2026-48780: Forem vulnerable to bypass of email address domain restrictions
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Patch a2ab6d4 - Compensating control
Configure your SMTP server or email delivery provider to drop or refuse to send/accept maliciously crafted email addresses (i.e., reject malformed addresses) as a temporary workaround until the Forem code is patched with commit a2ab6d4.
Event History
Frequently Asked Questions
What is the severity of CVE-2026-48780?
The severity of CVE-2026-48780 is rated as high with a score of 8.2.
How do I fix CVE-2026-48780?
CVE-2026-48780 can be fixed by updating to the patched version following commit a2ab6d4.
What exploit does CVE-2026-48780 enable?
CVE-2026-48780 allows an attacker to bypass email address domain restrictions, potentially gaining access to invite-only Forem deployments.
What type of software is affected by CVE-2026-48780?
CVE-2026-48780 affects the Forem open-source software used for building communities.
What should I do if I cannot immediately update to patch CVE-2026-48780?
If you cannot update immediately, consider implementing a workaround by reviewing and tightening domain allowlist or denylist settings.