CVE-2026-77939: Flextype

Medium severity, CVSS 6.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Flextype CMS through v1.0.0-dev contains an expression language injection vulnerability that allows authenticated attackers with a valid API token to read arbitrary files by passing unsanitized user-supplied input to the Symfony ExpressionLanguage engine via the POST /api/v1/query endpoint. Attackers can leverage exposed application objects including filesystem() and serializers() within the evaluation scope to read arbitrary server files and achieve conditional remote code execution if a PHP file can be placed on disk through a secondary vector.

Affected products

• Flextype Flextype: up to and including 1.0.0-dev

Published 2026-08-28. Last modified 2026-09-08.