CVE-2026-34839: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in nicolargo glances
Glances versions prior to 4. 5. 4 have a vulnerability where the web server's REST API (/api/4/*) is accessible without authentication and allows cross-origin requests from any origin due to a permissive CORS policy. This enables malicious websites to read sensitive system information from a running Glances instance in the victim's browser, resulting in cross-origin data exfiltration. The issue is fixed in version 4. 5. 4.
AI Analysis
Technical Summary
The vulnerability in nicolargo Glances before version 4.5.4 involves the exposure of a REST API endpoint (/api/4/*) that is accessible without authentication and permits cross-origin requests from any origin via a permissive CORS header (Access-Control-Allow-Origin: *). This allows an attacker controlling a malicious website to perform cross-origin data exfiltration by reading sensitive system information from the victim's browser session where Glances is running. This issue extends previously known CORS problems affecting XML-RPC endpoints, but the REST API exposes more sensitive data. The vulnerability is tracked as CVE-2026-34839 with a CVSS 4.0 score of 7.7 (high severity).
Potential Impact
An attacker can exploit the permissive CORS policy on the Glances REST API to read sensitive system information from a victim's browser without authentication. This leads to unauthorized exposure of potentially critical system data. There are no reports of known exploits in the wild. The vulnerability affects all Glances versions prior to 4.5.4.
Mitigation Recommendations
Upgrade Glances to version 4.5.4 or later, where this vulnerability is patched. Since the vendor advisory confirms the issue is fixed in 4.5.4, applying this official fix fully mitigates the risk. No additional mitigations are required if the update is applied.
CVE-2026-34839: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in nicolargo glances
Description
Glances versions prior to 4. 5. 4 have a vulnerability where the web server's REST API (/api/4/*) is accessible without authentication and allows cross-origin requests from any origin due to a permissive CORS policy. This enables malicious websites to read sensitive system information from a running Glances instance in the victim's browser, resulting in cross-origin data exfiltration. The issue is fixed in version 4. 5. 4.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in nicolargo Glances before version 4.5.4 involves the exposure of a REST API endpoint (/api/4/*) that is accessible without authentication and permits cross-origin requests from any origin via a permissive CORS header (Access-Control-Allow-Origin: *). This allows an attacker controlling a malicious website to perform cross-origin data exfiltration by reading sensitive system information from the victim's browser session where Glances is running. This issue extends previously known CORS problems affecting XML-RPC endpoints, but the REST API exposes more sensitive data. The vulnerability is tracked as CVE-2026-34839 with a CVSS 4.0 score of 7.7 (high severity).
Potential Impact
An attacker can exploit the permissive CORS policy on the Glances REST API to read sensitive system information from a victim's browser without authentication. This leads to unauthorized exposure of potentially critical system data. There are no reports of known exploits in the wild. The vulnerability affects all Glances versions prior to 4.5.4.
Mitigation Recommendations
Upgrade Glances to version 4.5.4 or later, where this vulnerability is patched. Since the vendor advisory confirms the issue is fixed in 4.5.4, applying this official fix fully mitigates the risk. No additional mitigations are required if the update is applied.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-30T20:52:53.284Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69e6b73b19fe3cd2cd3f2d13
Added to database: 4/20/2026, 11:31:07 PM
Last enriched: 4/20/2026, 11:46:18 PM
Last updated: 4/21/2026, 1:08:48 AM
Views: 5
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