CVE-2025-66296: Grav vulnerable to Privilege Escalation in Grav Admin: Missing Username Uniqueness Check Allows Admin Account Takeover

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-01 · updated 2026-09-26
Weakness: CWE-266

Description

Grav is a file-based Web platform. Prior to 1.8.0-beta.27, a privilege escalation vulnerability exists in Grav’s Admin plugin due to the absence of username uniqueness validation when creating users. A user with the create user permission can create a new account using the same username as an existing administrator account, set a new password/email, and then log in as that administrator. This effectively allows privilege escalation from limited user-manager permissions to full administrator access. This vulnerability is fixed in 1.8.0-beta.27.

Affected products

getgrav grav: from 1.7.49.5 before 1.8.0; 1.8.0-beta1, 1.8.0-beta10, 1.8.0-beta11, 1.8.0-beta12, 1.8.0-beta13, 1.8.0-beta14 (+20) — fixed in 1.8.0

How to fix

Upgrade to a fixed version: getgrav grav 1.8.0. Check the vendor advisory for mitigations.

References

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