CVE-2026-13164
Unauthenticated self-registration in MailerUp allows access to stored email data
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
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.8
Unauthenticated self-registration in MailerUp allows access to stored email data
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
- Record
CVE-2026-13164- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2026-38999
8.8
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
- Record
EUVD-2026-38999- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-cwqp-w2pg-8772
8.8
Missing Authentication for Critical Function (CWE-306) in the RegisterView (apps/accounts/views...
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
- Record
GHSA-cwqp-w2pg-8772- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
8.8
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
- Record
CVE-2026-13164- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-306
- Updated
- 2026-11-02
OSV
8.8
Unauthenticated self-registration in MailerUp allows access to stored email data
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
- Record
CVE-2026-13164- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-306
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-13164 is a high vulnerability (CVSS 8.8) in Mailerup, published June 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.71%, the 53rd percentile. No source names a fixed version.
References
github.com/Maalfer/mailerup/commit/99eb6d4586134bf3f4422093fbf47d6794ef0ee5
secur0.com/en/cna/cve-list/cve-2026-13164-unauthenticated-self-registration-in-mailerup-allows-access-to-stored-email-data
nvd.nist.gov/vuln/detail/CVE-2026-13164
github.com/advisories/GHSA-cwqp-w2pg-8772
github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13164.json
github.com/Maalfer/mailerup