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.
History

Fri, 24 Apr 2026 19:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:nicolargo:glances:*:*:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N'}


Wed, 22 Apr 2026 00:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 21 Apr 2026 00:45:00 +0000

Type Values Removed Values Added
First Time appeared Nicolargo
Nicolargo glances
Vendors & Products Nicolargo
Nicolargo glances

Mon, 20 Apr 2026 23:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
Weaknesses CWE-200
CWE-306
CWE-942
References
Metrics cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-04-20T23:09:02.551Z

Updated: 2026-04-21T19:37:42.399Z

Reserved: 2026-03-30T20:52:53.284Z

Link: CVE-2026-34839

cve-icon Vulnrichment

Updated: 2026-04-21T19:37:39.723Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-21T00:16:27.910

Modified: 2026-04-24T19:09:23.017

Link: CVE-2026-34839

cve-icon Redhat

No data.