CVE-2026-42843
HIGHGrav 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,…
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.
Description
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.
Affected Products
grav-plugin-apigetgravDetection & mitigation playbook
Vendor / applianceDetect
Inventory every getgrav grav-plugin-api deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-42843 yet — track the getgrav grav-plugin-api advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-42843 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-42843. 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-2026-42843 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-42843 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.