# CVE-2026-77939

## Summary

- **CVE ID:** CVE-2026-77939
- **Severity:** HIGH
- **CVSS Score:** 7.1 (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)
- **CWE:** CWE-94, CWE-1336
- **Published:** Aug 28, 2026
- **Last Modified:** Aug 29, 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.

## Affected Products

- flextype — flextype (0)

## References

- [CNA](https://github.com/flextype/flextype/issues/595)
- [CNA](https://www.vulncheck.com/advisories/flextype-cms-dev-rce-via-post-api-v1-query-endpoint)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.44%
- **EPSS Percentile:** 37.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._