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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.

PUBLISHED Reserved 2026-03-30 | Published 2026-04-02 | Updated 2026-04-02 | Assigner GitHub_M




HIGH: 8.3CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N

Problem types

CWE-918: Server-Side Request Forgery (SSRF)

Product status

< 2.21.3
affected

References

github.com/...iz-app/security/advisories/GHSA-89vp-m2qw-7v34

github.com/gitroomhq/postiz-app/releases/tag/v2.21.3

cve.org (CVE-2026-34576)

nvd.nist.gov (CVE-2026-34576)

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