RCE in As203038 Looking-Glass

CVE-2026-53611

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.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.020 (80.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 80.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53611: rose from 0.010 to 0.020.

EPSS over last 30 days · oldest: 0.010 · newest: 0.020 · change: +0.009

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-53611?
CVE-2026-53611 is a critical-severity vulnerability in As203038 Looking-Glass, classified under OS Command Injection. CVSS score: 9.8/10. Published 2026-09-02.
How severe is CVE-2026-53611?
Critical severity. CVSS v3 base score is 9.8 out of 10.