CVE-2026-34577Public exploitNetwork attack vector

Unauthenticated internal-resource disclosure via bypassable URL suffix

Published Apr 2, 2026 · Updated Apr 2, 2026

SSRF in Postiz before 2.21.3 allows remote attackers to read HTTP-accessible internal resources through GET /public/stream. PublicController passes the user-controlled url parameter to a full-response proxy after checking only that the string ends in mp4, so a query value or fragment can satisfy the suffix test. No authentication is required, and returned content can expose internal services or cloud metadata that the Postiz host can reach.

CVSS severity8.6
High
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in Postiz before 2.21.3 allows remote attackers to read HTTP-accessible internal resources through GET /public/stream. PublicController passes the user-controlled url parameter to a full-response proxy after checking only that the string ends in mp4, so a query value or fragment can satisfy the suffix test. No authentication is required, and returned content can expose internal services or cloud metadata that the Postiz host can reach.

The record

CVE
CVE-2026-34577
Published
Apr 2, 2026
Updated
Apr 2, 2026
Vendor
GitroomHQ
Product
Postiz
Classifications
CWE-918, CAPEC-664, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 2, 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=< 2.21.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GitroomHQ · Postizversion=< 2.21.3

Published CVSS scores

8.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
CAPEC-664Server Side Request Forgery
T1190Exploit Public-Facing Application

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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