Grav before 2.0.4 contains a regular expression denial of service (ReDoS) vulnerability in the regex_replace filter and function, which are allowlisted in the Twig content sandbox. When Twig processing in page content is enabled (security.twig_content.process_enabled: true, disabled by default), an authenticated page editor can supply a catastrophically backtracking PCRE pattern that is passed directly to PHP's preg_replace(), causing unbounded CPU consumption and denial of service to the web server process.

Grav contains a stored cross-site scripting vulnerability in shortcode-core attribute handlers where the XSS detection scan only matches payloads containing literal angle brackets, allowing shortcode parameters to bypass validation. Attackers with admin.pages permission can inject malicious JavaScript through shortcode attributes that execute in any viewer's browser, including administrators, enabling session hijacking via admin nonce theft.

Grav 2.0.4 (fixed in 2.0.7) contains a remote code execution vulnerability in Blueprint::dynamicData() (system/src/Grav/Common/Data/Blueprint.php), which passes a Class::method callable string and its arguments directly to call_user_func_array() without any allowlist. Because the form plugin routes page frontmatter through this path, an authenticated account with the admin.pages (or api.pages.write) permission can plant a malicious callable directive in a page. The command then executes as the web-server user whenever anyone — including an unauthenticated visitor — accesses the page.

The Grav api plugin (grav-plugin-api) before 1.0.8 fails to properly authorize API key generation and revocation: the plugin intercepts the apiKeyGenerate/apiKeyRevoke admin tasks before the account-management ACL runs and authorizes the caller on only the admin.login permission (the baseline permission held by every panel user). This allows any user with admin.login to mint a persistent API key bound to any account, and the forged key inherits the target account's API permissions. On installs where an API-enabled account holds broader permissions, this enables account impersonation and privilege escalation up to account takeover.

grav-plugin-login before 3.8.11 contains a cross-site request forgery (CSRF) vulnerability in the login.regenerate2FASecret frontend task, which regenerates and persists a new TOTP secret for the authenticated session user without any anti-CSRF nonce or Origin/Referer check. Because Grav core dispatches the task from the GET 'task:' URI parameter and the default session cookie is SameSite=Lax, an attacker can lure a logged-in victim to an off-site page that performs a top-level GET navigation, rotating the victim's TOTP secret so their enrolled authenticator no longer matches the server, effectively forcing 2FA re-enrollment. Sites configured with session.samesite: Strict are not affected.

grav-plugin-api before 1.0.6 fails to validate super-admin status in createApiKey, generate2fa, and disable2fa endpoints, allowing non-super api.users.write managers to escalate to super-admin. Attackers can mint API keys bound to super-admin accounts or strip 2FA from super-admin users to achieve full instance takeover.

Grav before 2.0.4 ships a default .htaccess (and reference webserver-configs/htaccess.txt) whose rules blocking access to sensitive file types (.yaml, .php, .json, etc.) lack the [NC] flag, making extension matching case-sensitive. On case-insensitive filesystems (Windows/NTFS, macOS/HFS+, or Docker volume mounts), an unauthenticated attacker can request these files with uppercase or mixed-case extensions (e.g., .YAML, .PHP) to bypass the restrictions and read sensitive configuration files that may contain API keys and credentials.

The Grav API plugin (getgrav/grav-plugin-api) before 1.0.0-rc.16 shipped Access-Control-Allow-Origin: * as its default CORS configuration on all responses, including authenticated endpoints and preflight (OPTIONS) responses. Because the plugin accepts credentials via the Authorization and X-API-Token headers (set programmatically by JavaScript rather than via cookies), an attacker who obtains a valid access token (e.g., via log leakage, Referer headers, browser history, or network capture) can issue fully authenticated cross-origin requests from any malicious website to read sensitive data and perform write operations as the token's user. Fixed in 1.0.0-rc.16.

Grav before 2.0.4 contains a two-factor authentication bypass vulnerability in the login plugin where the regenerate2FASecret task checks only user existence, not authorization, during the pending TOTP challenge window. Attackers who know the victim's password can call this task without a CSRF nonce to overwrite the 2FA secret with an attacker-chosen value, compute a valid TOTP code, and complete authentication while reducing 2FA to password-only protection.

Grav Flex-Objects before version 1.4.3 contains a broken access control vulnerability in the admin-next REST API that allows authenticated users with only api.access permission to perform unauthorized CRUD operations on permission-less directories. Attackers with api.access credentials can create, read, update, delete, and export objects from any directory lacking an explicit permissions configuration, bypassing intended authorization controls.