CVE-2026-57852 Authentication Bypass via Null Short-Circuit in Grav CMS Scheduler Webhook Token Check
Unauthenticated attackers can bypass webhook token validation to execute scheduled jobs, leading to remote code execution under the web server user.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-57852?
CVE-2026-57852 is a medium-severity authentication bypass vulnerability in Trilby Media Grav CMS scheduler-webhook plugin, published on 20 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Grav CMS scheduler-webhook plugin contains an authentication bypass vulnerability that allows unauthenticated remote attackers to trigger configured scheduled jobs by exploiting a short-circuit logic flaw in the webhook token validation. Attackers can send a single unauthenticated POST request to the scheduler webhook endpoint to execute all configured scheduled jobs or target a specific job, causing unintended execution of operator-defined commands under the web server process user.
Weakness: CWE-303
Which versions are affected by CVE-2026-57852?
How do I fix CVE-2026-57852?
No fix has been published for CVE-2026-57852 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-57852 being exploited?
There is no known exploitation of CVE-2026-57852 in the wild and no public exploit code.
Sources
Also known as GHSA-4p4x-7xpg-55gw.