CVE-2026-13164
Unauthenticated self-registration in MailerUp allows access to stored email data
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
INFO
Published Date :
June 24, 2026, 5:16 p.m.
Last Modified :
June 25, 2026, 7:58 p.m.
Remotely Exploit :
Yes !
Source :
4daa8cea-433a-44bd-9456-53b127fc289a
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 4.0 | HIGH | 4daa8cea-433a-44bd-9456-53b127fc289a | ||||
| CVSS 4.0 | HIGH | 4daa8cea-433a-44bd-9456-53b127fc289a |
Solution
- Implement proper authentication for the registration endpoint.
- Enable email verification or admin approval for registrations.
- Restrict access to stored emails based on user roles.
- Apply necessary security patches for MailerUp.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-13164.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-13164 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-13164
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-13164 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-13164 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 4daa8cea-433a-44bd-9456-53b127fc289a
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/Maalfer/mailerup', 'vendor': 'Mailerup', 'product': 'Mailerup', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '1.0.1', 'versionType': 'custom'}], 'defaultStatus': 'unaffected'}] Added 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 Added CVSS V4.0 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 Added CWE CWE-306 Added Reference https://github.com/Maalfer/mailerup/commit/99eb6d4586134bf3f4422093fbf47d6794ef0ee5 Added Reference https://secur0.com/en/cna/cve-list/cve-2026-13164-unauthenticated-self-registration-in-mailerup-allows-access-to-stored-email-data -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 24, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-13164', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-06-24T16:42:15.974524Z'}