Flextype CMS 1.0.0-dev RCE via POST /api/v1/query Endpoint (CVE-2026-77939) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-77939

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

Answer in brief

CVE-2026-77939 records a Unknown severity vulnerability in Flextype CMS 1.0.0-dev RCE via POST /api/v1/query Endpoint. The current sources do not mark it as known exploited. The current feed maps flextype/flextype (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 28, 2026Updated Aug 28, 2026Source checked Aug 28, 2026First seen by HOL Aug 28, 2026Material review Aug 28, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps flextype/flextype (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
flextype/flextypegeneric	0 \|\| 0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for flextype/flextype.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 28, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.