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.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-1336",
"CWE-94"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77939.json",
"unresolved_ranges": [
{
"extracted_events": [
{
"last_affected": "1.0.0-dev"
}
],
"source": "AFFECTED_FIELD"
}
]
}