high CVSS 8.8

CVE-2026-27899·Docker vulnerability

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.

Severity
high
Software
Docker
Fixed in
2.1.3
Published
2026-02-26

Affected versions

Until: 2.1.3

Fixed in: 2.1.3

How to fix this CVE

Update WireGuard Portal (running in Docker) to version 2.1.3 or later to patch a privilege escalation flaw that allows authenticated users to grant themselves administrator access. If you are using the official Docker image, pull the latest tag or explicitly use wg-portal:2.1.3 or newer. Redeploy your container and verify no unauthorized admin accounts were created during the exposure window.

sudo dnf update docker-ce

Defensia detects this vulnerability

What an exploitation attempt looks like

Sample log line indicative of exploitation attempts:

PUT /api/users/[user-id] HTTP/1.1.*\"IsAdmin\"\s*:\s*true

WAF mitigation (if patching is not yet possible)

Add this rule to your WAF to block exploitation attempts while you schedule the patch. 

Implement a WAF rule to block PUT/PATCH requests to user profile endpoints that contain the 'IsAdmin' field in the JSON body from non-administrative source IPs or roles. Return HTTP 403 Forbidden for such requests and log them for security review.

How to check if you are affected

  1. Run 'docker --version' and 'docker images' to list installed Docker versions and running containers; check for wg-portal image tags older than 2.1.3
  2. Execute 'docker inspect <container_id> | grep -i image' to confirm the exact wg-portal version tag deployed
  3. Query the WireGuard Portal database directly or via its API endpoint (if accessible) to enumerate user accounts with 'IsAdmin' flag set to true; compare against your known admin list
  4. Review application logs from the wg-portal container using 'docker logs <container_id>' for PUT requests to '/api/users/profile' or similar endpoints from non-admin source IPs with timestamps of suspicious account privilege escalations

Indicators of compromise

  • PUT request to /api/users/profile or /api/users/{id} containing "IsAdmin": true
  • Spike in successful PUT requests to user endpoints from internal authenticated users
  • New admin-level user accounts created via API during the vulnerability window

FAQ

What is CVE-2026-27899?

CVE-2026-27899 is a privilege escalation vulnerability in WireGuard Portal that allows any authenticated user to self-promote to administrator by modifying their own user profile JSON to include an 'IsAdmin' field set to true. The server fails to validate and strip this protected attribute before writing changes to the database.

Is CVE-2026-27899 being actively exploited?

No, this vulnerability is not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog, and no public exploits have been disclosed. However, the attack is trivial to execute and requires only basic HTTP knowledge.

What versions of Docker are affected by CVE-2026-27899?

This CVE affects WireGuard Portal running inside Docker containers with versions prior to 2.1.3. The vulnerability exists in wg-portal itself, not Docker; however, Docker users deploying wg-portal images before tag 2.1.3 are impacted.

How do I check if my server is vulnerable to CVE-2026-27899?

Run 'docker images | grep wg-portal' to identify deployed versions; if the tag is below 2.1.3 or uses 'latest' from before the fix date, the container is vulnerable. Additionally, check your WireGuard Portal admin user count for unexpected additions.

Does Defensia detect CVE-2026-27899?

Yes — Defensia's CVE advisory scanner compares installed package versions against the NVD database. If Docker and wg-portal are installed on a monitored server, CVE-2026-27899 will appear in your dashboard with remediation steps.

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References

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