CVE-2026-31863: Anytype Heart's gRPC API client challenge verification can be bypassed on localhost

The challenge-based authentication for the local gRPC client API can be bypassed, allowing an attacker to gain access without the 4-digit code.

Affected components:

• Anytype Desktop (all platforms) ≤ v0.48.2
• Anytype-CLI (headless deployments) ≤ v0.1.9

Not affected:

• Anytype mobile apps (iOS, Android) - do not expose a local gRPC server

Who is impacted: This vulnerability is scoped to localhost. The gRPC and gRPC-Web ports bind to 127.0.0.1 only and are not exposed to the local network or internet.