CVE-2026-34577 | Postiz: Unauthenticated Full-Read SSRF via /public/stream Endpoint with Trivially Bypassable Extension Check

Exp

Postiz is an AI social media scheduling tool. Prior to version 2.21.3, the GET /public/stream endpoint in PublicController accepts a user-supplied url query parameter and proxies the full HTTP response back to the caller. The only validation is url.endsWith('mp4'), which is trivially bypassable by appending .mp4 as a query parameter value or URL fragment. The endpoint requires no authentication and has no SSRF protections, allowing an unauthenticated attacker to read responses from internal services, cloud metadata endpoints, and other network-internal resources. This issue has been patched in version 2.21.3.

Published: 2026-04-02 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-34577 is rated High Exploit Risk (62.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.47%). 1 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2026-34577

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-34577

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.16% 0.47% +0.32%
2 2026-05-14 0.09% 0.16% +0.07%
3 2026-04-03 — 0.09% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-34577

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.6 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 4.0 [email protected]

Weakness enumeration for CVE-2026-34577

Affected software / configurations for CVE-2026-34577

Vendor Product Version Raw CPE
gitroom postiz < 2.21.3 cpe:2.3:a:gitroom:postiz:*:*:*:*:*:*:*:*

References for CVE-2026-34577

cvelogic Threat Intelligence