Payload has a tenant authorization bypass in Multi-Tenant Plugin

## Impact When using the default tenant array field access, an authenticated user could assign themselves to other tenants. **You are affected if:** - You are using `@payloadcms/plugin-multi-tenant` If you configure the tenants arrayFieldAccess.create/update functions, a secured replacement membership field, you are not affected by this specific default behavior. ## Patches Users should upgrade Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`. ## Workarounds Configure tenants arrayFieldAccess.create and tenants arrayFieldAccess.update so only trusted users authorized for all tenants can modify memberships. Source Code Location: https://github.com/payloadcms/payload Affected Packages: - npm:@payloadcms/plugin-multi-tenant, affected < 3.90.0, patched in 3.90.0 - npm:@payloadcms/plugin-multi-tenant, affected >= 4.0.0-canary.0, < 4.0.0-canary.34, patched in 4.0.0-canary.34 CWEs: - CWE-862: Missing Authorization CVSS: - CVSS_V4: score 7.1, CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N References: - https://github.com/payloadcms/payload/security/advisories/GHSA-p96c-xwx8-3cqj - https://nvd.nist.gov/vuln/detail/CVE-2026-105860 - https://github.com/payloadcms/payload/commit/19b58692d20d3947f31124bf7a88ac14a5ebf02e - https://github.com/payloadcms/payload/releases/tag/v3.90.0 - https://github.com/advisories/GHSA-p96c-xwx8-3cqj