CVE-2026-27567: Payload has Server-Side Request Forgery (SSRF) in External File URL Uploads

Severity: medium (CVSS 4.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-02-24 · updated 2026-06-17
Weakness: CWE-918

Description

Payload is a free and open source headless content management system. Prior to 3.75.0, a Server-Side Request Forgery (SSRF) vulnerability exists in Payload's external file upload functionality. When processing external URLs for file uploads, insufficient validation of HTTP redirects could allow an authenticated attacker to access internal network resources. The Payload environment must have at least one collection with `upload` enabled and a user who has `create` access to that upload-enabled collection in order to be vulnerable. An authenticated user with upload collection write permissions could potentially access internal services. Response content from internal services could be retrieved through the application. This vulnerability has been patched in v3.75.0. As a workaround, one may mitigate this vulnerability by disabling external file uploads via the `disableExternalFile` upload collection option, or by restricting `create` access on upload-enabled collections to trusted users only.

Affected products

payloadcms payload: before 3.75.0 — fixed in 3.75.0

How to fix

Upgrade to a fixed version: payloadcms payload 3.75.0. Check the vendor advisory for mitigations.

References

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