PT-2026-33776 · Nicolargo · Glance

Published 2026-04-20 · Updated 2026-04-21 · CVE-2026-34839

Mitre

CVSS v4.0

8.7

High

AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

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.

Fix

Information Disclosure

Missing Authentication

Weakness Enumeration

CWE-200

CWE-306

CWE-942

Related Identifiers

CVE-2026-34839

Affected Products

Glance

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-34839 · Security Note
• https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9 · Note
• https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh · Note
• https://reddit.com/r/glances/comments/1sqrqk9/glances_454_is_released · Reddit Post