Postiz is an AI social media scheduling tool. Prior to version 2.21.3, the POST /public/v1/upload-from-url endpoint accepts a user-supplied URL and fetches it server-side using axios.get() with no SSRF protections. The only validation is a file extension check (.png, .jpg, etc.) which is trivially bypassed by appending an image extension to any URL path. An authenticated API user can fetch internal network resources, cloud instance metadata, and other internal services, with the response data uploaded to storage and returned to the attacker. This issue has been patched in version 2.21.3.

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History

Thu, 02 Apr 2026 20:30:00 +0000

Type Values Removed Values Added
Description Postiz is an AI social media scheduling tool. Prior to version 2.21.3, the POST /public/v1/upload-from-url endpoint accepts a user-supplied URL and fetches it server-side using axios.get() with no SSRF protections. The only validation is a file extension check (.png, .jpg, etc.) which is trivially bypassed by appending an image extension to any URL path. An authenticated API user can fetch internal network resources, cloud instance metadata, and other internal services, with the response data uploaded to storage and returned to the attacker. This issue has been patched in version 2.21.3.
Title Postiz: SSRF in upload-from-url endpoint allows fetching internal resources and cloud metadata
Weaknesses CWE-918
References
Metrics cvssV4_0

{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-04-02T18:57:33.241Z

Reserved: 2026-03-30T16:56:30.998Z

Link: CVE-2026-34576

cve-icon Vulnrichment

Updated: 2026-04-02T18:57:28.329Z

cve-icon NVD

Status : Received

Published: 2026-04-02T18:16:30.180

Modified: 2026-04-02T18:16:30.180

Link: CVE-2026-34576

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses