Description
Glances is an open-source system cross-platform monitoring tool. Prior to 4.5.5, the Glances XML-RPC server (glances -s) introduced a configurable CORS origin list in version 4.5.3 as a mitigation for CVE-2026-33533. However, the implementation silently falls back to Access-Control-Allow-Origin: * whenever cors_origins contains more than one entry. An operator who configures an explicit two-entry allowlist (e.g. two internal dashboard origins) intending to restrict browser access instead receives the unrestricted wildcard. A malicious web page served from any origin can issue a CORS simple request to /RPC2 and read the full system monitoring dataset without the victim's knowledge. This vulnerability is fixed in 4.5.5.
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Affected products
- nicolargo / glances< 4.5.5 – < 4.5.5