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CVE-2026-34839 Detail

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-BT 7.7 HIGH
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

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9 GitHub, Inc.
https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh CISA-ADP, GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-200 Exposure of Sensitive Information to an Unauthorized Actor GitHub, Inc.  
CWE-306 Missing Authentication for Critical Function GitHub, Inc.  
CWE-942 Permissive Cross-domain Policy with Untrusted Domains GitHub, Inc.  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-34839
NVD Published Date:
04/20/2026
NVD Last Modified:
04/21/2026
Source:
GitHub, Inc.