CVE-2025-66303

Description

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27.

CVSS v3.1 Score

4.9

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption

Affected Products

Vendor	Product	Versions
getgrav	grav	< 1.8.0
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All
getgrav	grav	All

References

Advisories & Patches

https://github.com/getgrav/grav/commit/9d11094e4133f059688fad1e00dbe96fb6e3ead7

Exploits

https://github.com/getgrav/grav/security/advisories/GHSA-x62q-p736-3997 https://github.com/getgrav/grav/security/advisories/GHSA-x62q-p736-3997

Frequently Asked Questions

What is CVE-2025-66303? +

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, A Denial of Service (DoS) vulnerability has been identified in Grav related to the handling of scheduled_at parameters. Specifically, the application fails to properly sanitize input for cron expressions. By manipulating the scheduled_at parameter with a malicious input, such as a single quote, the application admin panel becomes non-functional, causing significant disruptions to administrative operations. The only way to recover from this issue is to manually access the host server and modify the backup.yaml file to correct the corrupted cron expression. This vulnerability is fixed in 1.8.0-beta.27. It has a CVSS v3.1 base score of 4.9 (MEDIUM).

How severe is CVE-2025-66303? +

CVE-2025-66303 has a CVSS v3.1 score of 4.9 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2025-66303? +

CVE-2025-66303 affects products from getgrav, specifically: grav. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66303? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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