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

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.

Published: 2026-02-25 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-27899 is rated Moderate Risk (43.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.31%). Mandatory action: Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-27899

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.07% 0.31% +0.24%
2 2026-02-26 0.07%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-27899

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-27899

GitHub Security Advisory for CVE-2026-27899

GHSA-5rmx-256w-8mj9 · Severity: high · Ecosystem: go — WireGuard Portal is Vulnerable to Privilege Escalation via User Self-Update to Admin Level

Affected software / configurations for CVE-2026-27899

Vendor Product Version Raw CPE
wgportal wireguard_portal < 2.1.3 cpe:2.3:a:wgportal:wireguard_portal:*:*:*:*:*:*:*:*

References for CVE-2026-27899

cvelogic Threat Intelligence