Payload: Remote Code Execution through first-register

### Impact A crafted request to the public first-register operation can be used to perform a RCE exploit. **You are affected if:** - You use local auth strategy and your application remains without an initial user created ## Patches In the patched version data submission to create first user is properly sanitized. Users should upgrade Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`. Source Code Location: https://github.com/payloadcms/payload Affected Packages: - npm:payload, affected < 3.90.0, patched in 3.90.0 - npm:payload, affected >= 4.0.0-canary.0, < 4.0.0-canary.34, patched in 4.0.0-canary.34 CWEs: - CWE-94: Improper Control of Generation of Code ('Code Injection') - CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') CVSS: - Primary: score 8.1, CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - CVSS_V3: score 8.1, CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H References: - https://github.com/payloadcms/payload/security/advisories/GHSA-97rh-rhh2-7vjv - https://nvd.nist.gov/vuln/detail/CVE-2026-105858 - https://github.com/payloadcms/payload/commit/e947fc4ba4a434f276d043386e501b1d14eda679 - https://github.com/payloadcms/payload/releases/tag/v3.90.0 - https://github.com/advisories/GHSA-97rh-rhh2-7vjv