CVE-2026-34590

Postiz is an AI social media scheduling tool. Prior to version 2.21.4, the POST /webhooks/ endpoint for creating webhooks uses WebhooksDto which validates the url field with only @IsUrl() (format check), missing the @IsSafeWebhookUrl validator that blocks internal/private network addresses. The update (PUT /webhooks/) and test (POST /webhooks/send) endpoints correctly apply @IsSafeWebhookUrl. When a post is published, the orchestrator fetches the stored webhook URL without runtime validation, enabling blind SSRF against internal services. This issue has been patched in version 2.21.4.

• CWE-918

• https://github.com/gitroomhq/postiz-app/commit/5ae4c950db6aa516a31454b7a45b9480bca40a11Patch
• https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.4Product, Release Notes
• https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-wc9c-7cv8-m225Exploit, Mitigation, Vendor Advisory

Published

Apr 2, 2026

Last Modified

Jul 24, 2026

Status

Analyzed

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