CVE-2026-13164 Unauthenticated self-registration in MailerUp allows access to stored email data
Unauthenticated attackers can self-register accounts to read all stored emails due to missing authorization checks in the registration endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-13164?
CVE-2026-13164 is a high-severity missing authorization vulnerability in Mailerup, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Missing Authentication for Critical Function (CWE-306) in the RegisterView (apps/accounts/views.py), exposed at POST /api/auth/register/, in MailerUp <1.0.1 allows a remote, unauthenticated attacker to self-register a working account on instances where registration is intended to be restricted, because the endpoint applies the AllowAny permission with no email verification, CAPTCHA, or administrator approval. Any account created this way can read all email stored by the instance, resulting in full disclosure of stored messages to an arbitrary unauthenticated attacker
Weakness: CWE-306
Which versions are affected by CVE-2026-13164?
How do I fix CVE-2026-13164?
No fix has been published for CVE-2026-13164 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-13164 being exploited?
There is no known exploitation of CVE-2026-13164 in the wild and no public exploit code.
Sources
Also known as GHSA-cwqp-w2pg-8772.