CVE-2026-53611: AS203038 Looking-Glass

Critical severity, CVSS 9.8. EPSS: 2% chance of exploitation in the next 30 days.

Looking Glass is a modern, stateless network-diagnostic platform — a single self-contained Go binary that fronts a fleet of routers over SSH and exposes ping / traceroute / BGP lookups through a gRPC (ConnectRPC) API, an embedded SvelteKit web UI, and a lg-cli client. Prior to version 1.3.5, there is an OS Command Injection vulnerability resulting from an unanchored regular expression in the input validation layer. This issue has been patched in version 1.3.5.

Affected products

• AS203038 Looking-Glass: before 1.3.5 (fixed in 1.3.5)

Published 2026-09-02. Last modified 2026-09-09.