CVE-2026-34839 — Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.4, the Glances web server exposes a REST API (`/api/4/*`) that is accessible without authen…
Published: 2026-04-20 · CVSS: 7.7 · CVSS 4.0
Glances is an open-source system cross-platform monitoring tool. Prior to version 4.5.4, the Glances web server exposes a REST API (`/api/4/*`) that is accessible without authentication and allows cross-origin requests from any origin due to a permissive CORS policy (`Access-Control-Allow-Origin: *`). This allows a malicious website to read sensitive system information from a running Glances instance in the victim’s browser, leading to cross-origin data exfiltration. While a previous advisory exists for XML-RPC CORS issues, this report demonstrates that the REST API (`/api/4/*`) is also affected and exposes significantly more sensitive data. Version 4.5.4 patches the issue.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7