Is this vulnerability remotely exploitable over the internet?

Yes. As long as the `/public/stream` endpoint is exposed, an unauthenticated attacker on the internet can send crafted requests and cause the server to fetch internal or external URLs on their behalf.

Does exploitation require authentication or a valid user account?

No. The vulnerable endpoint does not enforce authentication, so any party with network access to the Postiz HTTP interface can attempt exploitation.

What is the safest general fix pattern for this class of bug?

The most robust fix pattern is to eliminate arbitrary user-controlled proxying: replace open URL fetching with allow-listed, application-defined destinations, coupled with strict URL parsing and network egress controls that block access to internal and metadata endpoints.

Severity:

HIGH RISK

(8.6)

Server-Side Request Forgery (CWE-918) in Postiz Public Stream Proxy Endpoint

CVE-2026-34577

Published:

Apr 2, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-94

HIGH RISK

HIGH

(8.8)

PHP Code Injection via File Upload (CWE-94) in Aero CMS Admin Post Creation

Remote Code Execution by authenticated users via malicious file upload

May 10, 2026

CWE-94

HIGH RISK

HIGH

(8.8)

Code Injection (CWE-94) via Module Parameters in Evolution CMS

Remote Code Execution by Authenticated Users

May 10, 2026

Vulnerability Type

Category:

Server-Side Request Forgery (SSRF)

CWE:

CWE-918

Impact:

Exposure of internal services and metadata via server-initiated HTTP requests

Severity:

HIGH RISK

(8.6)

CVSS Version:

3.1

Vulnerability Type

Category:

Server-Side Request Forgery (SSRF)

CWE:

CWE-918

Impact:

Exposure of internal services and metadata via server-initiated HTTP requests

Severity:

HIGH RISK

(8.6)

CVSS Version:

3.1

Catch This CVE While Code Is Being Written

Detect vulnerable code directly in pull requests, so CVEs are fixed before merge.

Get Started

Ship clean & secure code faster

Start Free Trial

Get Pentest Report

Ship clean & secure code faster

Start Free Trial

Get Pentest Report

Ship clean & secure code faster

Start Free Trial

Get Pentest Report

CodeAnt AI is an offensive and defensive security platform.

Defensive + offensive security.

From first line of code to a pentest
that knows every line of it.

SOC 2 Type II certified | CodeAnt AI is independently audited and compliant with SOC 2 Type II security standards

Ask AI for summary of CodeAnt

Defensive + offensive security.

From first line of code to a pentest
that knows every line of it.

Ask AI for summary of CodeAnt

Defensive + offensive security.

From first line of code to a pentest
that knows every line of it.

Ask AI for summary of CodeAnt

Server-Side Request Forgery (CWE-918) in Postiz Public Stream Proxy Endpoint

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.8)

PHP Code Injection via File Upload (CWE-94) in Aero CMS Admin Post Creation

HIGH RISK

HIGH

(8.8)

Code Injection (CWE-94) via Module Parameters in Evolution CMS

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

Product

Compare

Company

Developers

Legal

Product

Compare

Company

Developers

Legal

Product

Compare

Company

Developers

Legal