CVE-2026-58200

Payload Plugins is a collection of plugins designed to enhance Payload CMS. From 0.3.0 until 0.4.0, @jhb.software/payload-cloudinary-plugin deployments with clientUploads enabled expose POST /api/cloudinary-generate-signature, whose handler in cloudinary/src/getGenerateSignature.ts passes attacker-controlled body.paramsToSign directly to cloudinary.utils.api_sign_request without a key allowlist, collection policy, timestamp freshness check, or configured-folder enforcement. Any authenticated Payload user can obtain a valid Cloudinary HMAC-SHA1 signature for unauthorized parameters such as overwrite, type, notification_url, invalidate, folder, and public_id. The signature can authorize asset replacement, upload visibility changes, callbacks to attacker-selected URLs, cache invalidation, and uploads outside the intended folder. The client-visible Cloudinary API key is expected by the upload design, but the unrestricted server-side signature supplies the authorization value needed to complete these operations. This vulnerability is fixed in 0.4.0.

• https://github.com/jhb-software/payload-plugins/commit/da2325901c5eeced17d33a1b2e647e300b8cbff2
• https://github.com/jhb-software/payload-plugins/pull/155
• https://github.com/jhb-software/payload-plugins/releases/tag/cloudinary@0.4.0
• https://github.com/jhb-software/payload-plugins/security/advisories/GHSA-h5x8-xp6m-x6q4