Craft CMS: Authenticated leak of secret environment variablesGHSA-596p-6jv8-775v
GHSA-596p-6jv8-775v is a CWE-668 vulnerability in craftcms/cms. A fix is available for craftcms/cms — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-596p-6jv8-775v.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
craftcms/cms🐘craftcms/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Environment variables and secrets are interpolated into a Twig template even when the Twig sandbox is enabled, allowing them to be leaked by an authenticated attacker.
The Craft vulnerability CVE-2026-31857 was only patched by applying sandboxed Twig templating. This theoretically protects Craft CMS against RCE attacks, provided the sandbox is enabled and secure, with no known bypasses.
However, the same request parameter elementId, which allows for sandboxed Twig templates to be rendered, also includes functionality that interpolates referenced environment variables. If the parameter includes a string of the form ${ENV_VAR} then the string is replaced with the environment variable or secret from a secrets file with that name.
Afterward, the string is rendered as a Twig template. If the sandbox is disabled, Twig templates can already gain RCE or access environment variables using the getenv function. Sandboxed Twig templates should not have this access, but now do thanks to this additional environment-variable replacement behavior.
The template’s resulting value is not directly reflected in the response. To exfiltrate the value, the sandboxed Twig template cannot use network functions. But it can use a blind error-based approach similar to blind SQL injection. With enough requests, any environment variable or secret can be incrementally leaked. This can be abused to forge a session, escalate privileges with the CRAFT_SECURITY_KEY, and steal credentials for the database, SMTP server, or other connected APIs or blob storage.
Impact
An authenticated attacker, with permission to access the control panel, can render a malicious Twig template and steal arbitrary environment variables and secrets with a large number of requests, even if the Twig sandbox is enabled through enableTwigSandbox().
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.10.6 | 5.10.6composer require craftcms/cms:^5.10.6 |
| 🐘Packagist | craftcms/cms | ≥ 4.0.0-RC1&&< 4.18.2 | 4.18.2composer require craftcms/cms:^4.18.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update craftcms/cms to 5.10.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-596p-6jv8-775v is resolved across your whole dependency graph.
Workarounds
Until you can upgrade, make sure every query built from user input uses parameterised statements or a prepared-statement API rather than string concatenation, and reduce the database account's privileges so an injected query cannot read or alter data beyond what the feature needs.
Frequently Asked Questions
Is GHSA-596p-6jv8-775v in your dependencies?
Find it across Packagist, including transitive dependencies.