CVE-2026-77939

Flextype CMS 1.0.0-dev RCE via POST /api/v1/query Endpoint

State: Published
Severity: 7.1 High
Published: Aug 28, 2026
Updated: Aug 29, 2026
Reserved: Aug 21, 2026

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.

Scores

CVSS	Score	Vector	Source
4.0	7.1 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N	VulnCheck
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N	VulnCheck

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')
CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine

Affected Products

Product	Versions
flextypeflextype	1.0.0-dev and earlierAffected aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d and earlierAffected

References

Researcher Disclosuretechnical-descriptionexploitissue-tracking
https://www.vulncheck.com/advisories/flextype-cms-dev-rce-via-post-api-v1-query-endpointthird-party-advisory

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