CVE-2026-77939Public exploitNetwork attack vector

Authenticated file read via unsanitized expression evaluation

Published Aug 28, 2026 · Updated Aug 29, 2026

Expression language injection in Flextype 1.0.0-dev allows remote authenticated users to read arbitrary server files through the query API. POST /api/v1/query passes each query value directly to parsers()->expressions()->eval(), exposing filesystem() and serializers() objects in its evaluation scope. Valid API and access tokens are required; code execution additionally requires a secondary vector that places a PHP file on disk.

CVSS severity7.1
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Expression language injection in Flextype 1.0.0-dev allows remote authenticated users to read arbitrary server files through the query API. POST /api/v1/query passes each query value directly to parsers()->expressions()->eval(), exposing filesystem() and serializers() objects in its evaluation scope. Valid API and access tokens are required; code execution additionally requires a secondary vector that places a PHP file on disk.

The record

CVE
CVE-2026-77939
Published
Aug 28, 2026
Updated
Aug 29, 2026
Vendor
Flextype
Product
Flextype
Classifications
CWE-94, CWE-1336, T1190, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 29, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=1.0.0-dev
  2. Affected versionversion=0 <=aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Flextype · Flextypeversion=0 <=1.0.0-dev; version=0 <=aea4ead8c449ea5517ed53b6dcbd28b0a528ad9d

Published CVSS scores

6.5Public vulnerability disclosureCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
7.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
T1190Exploit Public-Facing Application
T1005Data from Local System

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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