Auth bypass in Getgrav Grav-Plugin-Api

CVE-2026-42843

Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content, media, configuration, users, and system management. Prior to 1.0.0-beta.15, an insecure direct object reference and logic flaw in the Grav API plugin (UsersController::update) allows any authenticated user with basic API access (api.access) to modify their own permission configuration. An attacker can exploit this to escalate their privileges to Super Administrator (admin.super and api.super), leading to full system compromise and potential RCE. This vulnerability is fixed in 1.0.0-beta.15.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (40.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42843: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42843?
CVE-2026-42843 is a high-severity vulnerability in Getgrav Grav-Plugin-Api, classified under Incorrect Authorization. CVSS score: 8.8/10. Published 2026-05-11.
How severe is CVE-2026-42843?
High severity. CVSS v3 base score is 8.8 out of 10.