Cyber Posture

CVE-2026-34406

HighPublic PoC

Published: 31 March 2026

Published
31 March 2026
Modified
10 April 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0041 61.3th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

APTRS (Automated Penetration Testing Reporting System) is a Python and Django-based automated reporting tool designed for penetration testers and security organizations. Prior to version 2.0.1, the edit_user endpoint (POST /api/auth/edituser/<pk>) allows Any user who can reach that endpoint and submit…

more

crafted permission to escalate their own account (or any other account) to superuser by including "is_superuser": true in the request body. The root cause is that CustomUserSerializer explicitly includes is_superuser in its fields list but omits it from read_only_fields, making it a writable field. The edit_user view performs no additional validation to prevent non-superusers from modifying this field. Once is_superuser is set to true, gaining unrestricted access to all application functionality without requiring re-authentication. This issue has been patched in version 2.0.1.

Mitigating Controls (NIST 800-53 r5)AI

prevent

AC-3 requires enforcement of approved authorizations, directly addressing the lack of validation in the edit_user endpoint that allowed unauthorized modification of the is_superuser field.

prevent

AC-6 enforces least privilege, preventing low-privileged users from escalating to superuser via the vulnerable API endpoint.

prevent

AC-2 mandates proper account management including privilege assignment and review, which would mitigate unauthorized privilege changes in user accounts.

Security SummaryAI

CVE-2026-34406 is a privilege escalation vulnerability in APTRS (Automated Penetration Testing Reporting System), a Python and Django-based automated reporting tool for penetration testers and security organizations. Affecting versions prior to 2.0.1, the issue resides in the CustomUserSerializer used by the edit_user endpoint (POST /api/auth/edituser/<pk>). The serializer explicitly lists the is_superuser field but omits it from read_only_fields, rendering it writable. Additionally, the edit_user view lacks validation to prevent non-superusers from modifying this field. The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and is associated with CWE-915.

Any authenticated user with low privileges (PR:L) who can access the network-exposed endpoint (AV:N) can exploit this by submitting a crafted POST request with "is_superuser": true in the body, targeting their own account or any other <pk>. Successful exploitation escalates the targeted account to superuser status, granting unrestricted access to all application functionality without requiring re-authentication. This enables high-impact confidentiality, integrity, and availability violations.

The vulnerability has been patched in APTRS version 2.0.1. Security practitioners should upgrade to this version immediately. Relevant resources include the patching commit at https://github.com/APTRS/APTRS/commit/d1f1b3a5d1953082af8e075712ca29742e900d56, the release page at https://github.com/APTRS/APTRS/releases/tag/2.0.1, and the GitHub security advisory at https://github.com/APTRS/APTRS/security/advisories/GHSA-gv25-wp4h-9c35.

Details

CWE(s)

Affected Products

aptrs
aptrs
≤ 2.0.1

MITRE ATT&CK Enterprise TechniquesAI

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
Why these techniques?

The vulnerability enables low-privileged authenticated users to escalate privileges to superuser by exploiting a writable is_superuser field in the network-exposed edit_user API endpoint without proper validation, directly mapping to Exploitation for Privilege Escalation (T1068).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References