CVE-2026-27899 is a high-severity (CVSS 8.8) Improper Privilege Management vulnerability in github.com/h44z/wg-portal. A fix is available for github.com/h44z/wg-portal — see the affected versions and patch details below.
WireGuard Portal Vulnerable to Privilege Escalation to Admin via User Self-Update
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27899.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-27899 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/h44z/wg-portalReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Privilege Escalation to Admin via User Self-Update in wg-portal
Summary
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.
Tested against wg-portal v2.1.2 (Docker image wgportal/wg-portal:v2).
Root Cause
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.
Impact
After the exploit, the attacker has full admin access to the WireGuard VPN management portal. They can:
- Read and modify every user account
- Create, modify, and delete WireGuard peers on any interface
- View WireGuard interface configurations
- Disable or lock other user accounts
- Access the full user list and their API tokens
Patches
The problem was fixed in the latest release, v2.1.3. The docker images for the tag 'latest' built from the master branch also include the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/h44z/wg-portal | all versions | 2.1.3go get github.com/h44z/wg-portal@v2.1.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/h44z/wg-portal, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/h44z/wg-portal to 2.1.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27899 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-27899 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-27899. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-27899 in your dependencies?
O3 Security finds CVE-2026-27899 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.