CVE-2026-27899 WireGuard Portal Vulnerable to Privilege Escalation to Admin via User Self-Update
Authenticated users can escalate to admin by modifying their own profile JSON, granting full control over the WireGuard portal.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-27899?
CVE-2026-27899 is a high-severity vulnerability in h44z wg-portal, published on 26 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-27899?
3 open source packages ship an affected version, including github.com/h44z/wg-portal. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/h44z/wg-portal Go | All versions | None |
github.com/h44z/wg-portal Go | All versions | 2.1.3 |
github.com/h44z/wg-portal Go | All versions | 2.1.3 |
Products include Wgportal Wireguard Portal.
How do I fix CVE-2026-27899?
Upgrade github.com/h44z/wg-portal to 2.1.3 or later.
Is CVE-2026-27899 being exploited?
There is no known exploitation of CVE-2026-27899 in the wild and no public exploit code.
Sources
Also known as GHSA-5rmx-256w-8mj9, GO-2026-4566.