CVE-2026-34839
published 2026-04-21CVE-2026-34839: 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…
PriorityP338medium6.5CVSS 3.1
AVNACLPRNUIRSUCHINAN
EPSS
0.41%
32.6th percentile
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.
Affected
2 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| glances_project | glances | >= 0 < 4.5.4 | 4.5.4 |
| nicolargo | glances | < 4.5.4 | 4.5.4 |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
nvdv4.07.7HIGHCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
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Bugzilla
CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [fedora-all]
bugzilla·2026-04-21·CVSS 7.7
CVE-2026-34839 [HIGH] CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [fedora-all]
CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [epel-all]
bugzilla·2026-04-21·CVSS 7.7
CVE-2026-34839 [HIGH] CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [epel-all]
CVE-2026-34839 glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API [epel-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
Bugzilla
CVE-2026-34839 Glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API
bugzilla·2026-04-21·CVSS 7.7
CVE-2026-34839 [HIGH] CVE-2026-34839 Glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API
CVE-2026-34839 Glances: Glances: Information disclosure via permissive Cross-Origin Resource Sharing (CORS) policy in REST API
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
2026-04-21
Published