Medium severity · published Apr 2, 2026
CVE-2026-34590
Postiz: SSRF via Webhook Creation Endpoint Missing URL Safety Validation
5.4
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 13% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PO
postiz-app · gitroomhq
< 2.21.4 · source: vendor
PO
Postiz · Gitroom
before 2.21.4 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34590
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34590
Patch
https://github.com/gitroomhq/postiz-app/commit/5ae4c950db6aa516a31454b7a45b9480bca40a11
Product
https://github.com/gitroomhq/postiz-app/releases/tag/v2.21.4
Exploit
https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-wc9c-7cv8-m225
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