CVE-2026-11430

Description

Grav CMS's scheduler-webhook plugin contains an authentication bypass in the webhook token check. When the webhook feature is enabled but no webhookToken is configured, a compound conditional short-circuits and skips token validation, so an unauthenticated remote attacker who can reach POST /scheduler/webhook can trigger the operator's already-configured scheduled jobs by sending a single request. The primitive is triggering-existing-jobs, not attacker-chosen command execution: the attacker controls when the jobs run and which one runs (via ?job=), but does not control what the jobs do. Code execution follows only when the operator has configured a job that shells out, and even then the attacker controls timing rather than payload. Not a default-install issue: reaching the endpoint requires the separate scheduler-webhook GPM plugin to be installed, scheduler.modern.webhook.enabled to be true (default false), and no webhookToken to be configured; a stock Grav or Grav-Admin install exposes nothing here.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://github.com/getgrav/grav
• https://github.com/getgrav/grav/commit/694f1dae06d9061bbf0669c4291e3b206f998d71
• https://github.com/getgrav/grav/security/advisories/GHSA-xwv3-2mv2-w33x
• https://www.vulncheck.com/advisories/grav-cms-scheduler-webhook-authentication-bypass-via-null-short-circuit

CWEs

CWE-303