CVE-2026-50008: Parse Server: Server option routeAllowList is bypassable through batch sub-requests

Impact

The routeAllowList server option restricts external client access to a configured list of REST API routes. The check is only enforced as Express middleware against the outer HTTP request URL, so the /batch handler dispatches each sub-request to the internal router without re-running the allow-list check. An external caller whose outer route matches batch can issue batch sub-requests to any REST API route that the operator omitted from the allow-list.

Authentication, ACL, CLP, and other inner-route authorization controls still apply — only the operator-configured route firewall is bypassed.

Patches

routeAllowList is now re-enforced for each batch sub-request inside the batch handler before dispatch, mirroring the existing per-sub-request rate-limit enforcement pattern. The path-normalization and regex-match logic was extracted into a shared helper used by both the outer middleware and the batch handler. Master and maintenance keys bypass the per-sub-request check on the same terms as the outer middleware.

Workarounds

Operators who use routeAllowList and have allowlisted batch can mitigate without upgrading by explicitly including every inner route they intend to allow via batch in the allow-list (for example, routeAllowList: ['batch', 'classes/Public.', 'functions/allowedFunction']). This approach makes those inner routes reachable as direct REST requests as well, so it is broader than the post-patch behavior, but it eliminates the bypass.

Operators who do not configure routeAllowList are not affected. Parse Server v8 LTS is not affected because routeAllowList was introduced in v9.8.0.