Auth bypass in Getgrav Grav
CVE-2021-47812
GravCMS 1.10.7 contains an unauthenticated vulnerability that allows remote attackers to write arbitrary YAML configuration and execute PHP code through the scheduler endpoint. Attackers can exploit the admin-nonce parameter to inject base64-encoded payloads and create malicious custom jobs with system command execution.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.022 (82.1th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.021 · newest: 0.022 · change: +0.002
Affected products
- Getgrav Grav — versions 1.10.7
- Getgrav Gravcms — versions 1.10.7
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/49973 (Exploit, exploit)
- getgrav.org (Product, product)
- www.vulncheck.com/advisories/gravcms-arbitrary-yaml-writeupdate-unauthenticated (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2021-47812?
- CVE-2021-47812 is a critical-severity vulnerability in Getgrav Grav, classified under Missing Authorization. CVSS score: 9.8/10. Published 2026-01-16.
- How severe is CVE-2021-47812?
- Critical severity. CVSS v3 base score is 9.8 out of 10.