CVE-2026-48692: FastNetMon Community Edition through 1.2.9 exposes a gRPC API server on port 50052 with no authentication mechanism. The server is initialized with…

PriorityP352high8.1CVSS 3.1

AVAACLPRNUINSUCHIHAN

EPSS

0.23%

14.1th percentile

FastNetMon Community Edition through 1.2.9 exposes a gRPC API server on port 50052 with no authentication mechanism. The server is initialized with grpc::InsecureServerCredentials() (src/fastnetmon.cpp line 477) and a source code comment explicitly acknowledges 'Listen on the given address without any authentication mechanism.' None of the RPC methods in src/api.cpp (ExecuteBan, ExecuteUnBan, GetBanlist, GetTotalTrafficCounters, etc.) perform any credential verification. The ExecuteBan and ExecuteUnBan methods trigger security-critical actions: BGP route announcements that can blackhole network traffic, and execution of external notification scripts via popen(). An attacker with local network access can ban arbitrary IP addresses (causing denial of service to legitimate traffic), unban active attacks (disabling DDoS mitigation), and trigger script execution. There is also no role-based access control separating read-only monitoring from destructive administrative operations.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
pavel-odintsov	fastnetmon	<= 1.2.9	—

Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.