CVE-2026-100671
HighCVSS 8.0Exploitation Probability (EPSS)
Low risk19th percentile - higher than 19% of all known CVEs
Summary
Grav is a flat-file CMS. In versions 2.0.19 through 2.0.24 — and in 2.0.0 through 2.0.18 and 1.7.x only where content Twig has been explicitly enabled — page content authored by a user holding only page-write permission is rendered through a Twig sandbox that allowlists get_cookie(), which returns any cookie sent with the current request, including the visitor's session cookie. Grav then stores the finished post-Twig output in a page-content cache keyed only on page identity and the configuration checksum, with no session, user or request dimension.
Risk Assessment
A page published by a page-write user can capture the session identifier of the next administrator who views it, after which the cached output serves that identifier to unauthenticated visitors, who can replay the cookie to authenticate as that administrator. This leads to full administrator account takeover.
Recommendation
Update Grav to version 2.0.25 or later. Disable content Twig processing if not required and inspect the page-content cache for suspicious session data.
Other vulnerabilities in Grav
See all- CVE-2026-100668Medium
Grav 2.0.0 through 2.0.24 contain a Twig content sandbox escape. The `array` filter is allowlisted but lacks the sandbox guard, allowing access to the raw DI container and disclosure of the full configuration tree, including credentials and secrets, to anonymous visitors.
- CVE-2026-75837Critical
Grav before 2.0.14 fails to guard the access field in the core group blueprint with the required security@: admin.super restriction. A delegated admin.users operator can save a group with access[admin][super]=true to escalate to super-admin, gaining scheduler and Twig evaluation capabilities.
- CVE-2026-65008Critical
Grav 2.0.4 (fixed in 2.0.7) contains a remote code execution vulnerability in Blueprint::dynamicData(). The function 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 admin.pages (or api.pages.write) permission can plant a malicious callable directive in a page. The command executes as the web-server user whenever anyone – including an unauthenticated visitor – accesses the page.
- CVE-2026-61450Medium
Grav before version 2.0.2 contains a Twig sandbox bypass that allows a page author (any admin.pages user, or anyone able to write to user/pages) to exfiltrate configuration secrets. Although the sandbox replaces the 'config' variable with a redacted facade and strips Config::get/toArray from the method allowlist, the raw container remains accessible via the allow-listed grav.offsetGet('config'), which returns the real Config object. Allow-listed object-dumping filters (json_encode, print_r, yaml_encode) then serialize that object at the PHP level without invoking the sandbox method gate, exposing the full config tree including plugin secrets such as SMTP credentials, API keys, and plugin DB credentials.
- CVE-2025-66844Critical
In grav before 1.7.49.5, a SSRF (Server-Side Request Forgery) vector may be triggered via Twig templates when page content is processed by Twig and the configuration allows undefined PHP functions to be registered.
- CVE-2025-66301Critical
Grav is a file-based Web platform. Prior to 1.8.0-beta.27, due to improper authorization checks when modifying critical fields on a POST request to /admin/pages/{page_name}, an editor with only permissions to change basic content on the form is now able to change the functioning of the form through modifying the content of the data[_json][header][form] which is the YAML frontmatter which includes the process section which dictates what happens after a user submits the form which include some important actions that could lead to further vulnerabilities. This vulnerability is fixed in 1.8.0-beta.27.
- CVE-2026-117604High
Grav from 1.7.53.3 before 1.7.53.6 contains an authorization bypass in Debugger::isDebuggerRequestAuthorized() that allows unauthenticated visitors to read /__clockwork/ profiler data via a loopback REMOTE_ADDR fallback. Behind a same-host reverse proxy, remote requests appear as loopback, letting attackers read stored records including administrator plaintext passwords and configuration credentials.
- CVE-2026-116019High
Grav 2.0.15 before 2.2.13 contains an allowlist bypass vulnerability that allows page editors to invoke arbitrary public static methods by relocating data-*@ directives with unset-name@ or integer keys. Attackers with page-edit permission can embed crafted fields in Flex form overrides in page frontmatter to call methods like Folder::delete or Utils::download, deleting directories, overwriting files, or reading files outside the page tree.
- CVE-2026-114660Medium
Grav from 2.0.0 before 2.2.5 contains an improper access control vulnerability in FlexDirectory::dynamicFlexField() that allows page authors to call arbitrary Flex object methods via flex-*@ directives in page frontmatter. When a user with page edit rights opens the page, directives calling setStorageKey() and delete() run in their session, deleting protected pages neither account may delete.
- CVE-2026-114657Medium
Grav from 2.0.0 before 2.2.5 contains an information disclosure vulnerability that allows page authors to capture visitors' HTTP Basic credentials through Twig page content. Authors can print the request Uri object, which embeds PHP_AUTH_USER and PHP_AUTH_PW, inside an inline style background image to exfiltrate administrators' credentials to an external host.
Original NVD description (English source)
Grav is a flat-file CMS. In versions 2.0.19 through 2.0.24 — and in 2.0.0 through 2.0.18 and 1.7.x only where content Twig has been explicitly enabled — page content authored by a user holding only page-write permission is rendered through a Twig sandbox that allowlists get_cookie(), which returns any cookie sent with the current request, including the visitor's session cookie. Because the read occurs server-side via filter_input(INPUT_COOKIE, ...), the HttpOnly, Secure and SameSite attributes offer no protection. Grav then stores the finished post-Twig output in a page-content cache keyed only on page identity and the configuration checksum, with no session, user or request dimension and no bypass for authenticated visitors. A page published by a page-write user can therefore capture the session identifier of the next administrator who views it, after which the cached output serves that identifier to unauthenticated visitors, who can replay the cookie to authenticate as that administrator. Since 2.0.19, security.twig_content.process_enabled defaults to true and Security::applyTwigContentDefault() derives each page's process.twig flag from that gate, so content Twig runs on every page with no frontmatter or operator action. Fixed in 2.0.25; 1.7.x is outside the backport scope.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS