CVE-2026-115938 Low privilege condition filter escapes Twig sandbox, recovers "securityKey" and reaches RCE
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-115938?
CVE-2026-115938 is a high-severity vulnerability in craftcms cms, published on 23 Oct 2026.
Official description
Craft CMS allows any authenticated control panel user to submit an element-search condition whose element selector is evaluated as a sandboxed Twig object template. Craft’s allowed column filter delegates property lookup to Yii ArrayHelper, outside Twig’s SecurityPolicy. Repeated single-segment lookups therefore bypass the sandbox’s empty property/method allowlists.
The vulnerable condition value is ultimately cast to an integer. That does not protect the secret: the template can return author ID 1 when a guessed key character is correct and an impossible ID otherwise. The JSON endpoint returns entries for the first case and an empty array for the second, forming a stable remote character oracle.
After recovering GeneralConfig::securityKey, the same user can compute Craft’s generic HMAC wire format offline. Signed parameters such as redirect are then accepted and passed to unsandboxed View::renderObjectTemplate(), where Twig’s string-callable form can invoke native PHP callables. The regression proof uses the harmless substr() callback and observes abcdef becoming cdef; it does not execute an OS command.
Weakness: CWE-1336
Which versions are affected by CVE-2026-115938?
How do I fix CVE-2026-115938?
Upgrade to a fixed version.
Is CVE-2026-115938 being exploited?
There is no known exploitation of CVE-2026-115938 in the wild and no public exploit code.
Sources
Also known as GHSA-gg4p-9c93-5hfp, GHSA-v4q3-2g5g-wjj6.