CVE-2026-27899: WireGuard Portal Vulnerable to Privilege Escalation to Admin via User Self-Update

Vulnerability summary

CVE-2026-27899 is a high (CVSS 8.8) Improper Privilege Management vulnerability in h44z wg-portal. EPSS estimates a 0.35% chance of exploitation in the next 30 days, higher than 28.4% of scored vulnerabilities.

Timeline

1. 26-02-2026
   PublishedVulnerability first disclosed.
2. 26-02-2026
   Last modifiedVulnerability information updated.

Description

WireGuard Portal (or wg-portal) is a web-based configuration portal for WireGuard server management. Prior to version 2.1.3, any authenticated non-admin user can become a full administrator by sending a single PUT request to their own user profile endpoint with `"IsAdmin": true` in the JSON body. After logging out and back in, the session picks up admin privileges from the database. When a user updates their own profile, the server parses the full JSON body into the user model, including the `IsAdmin` boolean field. A function responsible for preserving calculated or protected attributes pins certain fields to their database values (such as base model data, linked peer count, and authentication data), but it does not do this for `IsAdmin`. As a result, whatever value the client sends for `IsAdmin` is written directly to the database. After the exploit, the attacker has full admin access to the WireGuard VPN management portal. The problem was fixed in v2.1.3. The docker images for the tag 'latest' built from the master branch also include the fix.

• CWE-269Improper Privilege ManagementThe product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.
• CWE-863Incorrect AuthorizationThe product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.