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[ CVE-2026-63116 · Published 21 Sep 2026 ]

deepstream: PATCH_MULTI action bypasses Valve permission system allowing unauthorized record writes

CVSS 8.8 EPSS <1%Fix available

[ Why it matters ]Priority signals

  • Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official description

deepstream is a server that allows clients and backend services to sync data, send messages and make rpcs at scale. From 10.1.0 until 10.1.1, src/services/permission/valve/rules-map.ts omits RECORD_ACTION.PATCH_MULTI from RULES_MAP. When an authenticated user sends a PATCH_MULTI record operation while permission.type is config, getRulesForMessage returns a null rule specification and ConfigPermission.canPerformAction treats the missing specification as an unconditional allow instead of applying RULE_TYPES.WRITE. Any authenticated user can therefore modify arbitrary protected records, corrupt application state, or cause service disruption; deployments using the default permission type none already allow all operations and are not additionally affected. This issue is fixed in version 10.1.1.

[ Fixes ]Fixes and patches

  • @deepstream/server 10.1.1Fixed version · GitHub Advisories · npm package @deepstream/server: upgrade to 10.1.1 or later (affected = 10.1.0)

[ Packages ]Affected open-source packages

[ References ]References