What’s Vulnerable › Vulnerabilities

CVE-2026-77939: Flextype CMS 1.0.0-dev RCE via POST /api/v1/query Endpoint

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-28 · updated 2026-09-08
• Weakness: CWE-94

Description

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: through 1.0.0-dev

References

• https://github.com/flextype/flextype/issues/595
• https://www.vulncheck.com/advisories/flextype-cms-dev-rce-via-post-api-v1-query-endpoint

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