VulnerabilityDeferred

CVE-2026-11430

Grav CMS's scheduler-webhook plugin contains an authentication bypass in the webhook token check.

MEDIUM 6.9EPSS 0.51%

Does this matter?

Lower severity and a low EPSS score (0.51%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 4.0: 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.51% probability · 42th percentile
CISA KEV: Not listed
Weakness: CWE-303
Source: disclosure@vulncheck.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.