{"id":"CVE-2026-34839","state":"PUBLISHED","title":"Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS","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.","publishedAt":"2026-04-20T23:09:02.551Z","updatedAt":"2026-04-21T19:37:42.399Z","severity":{"score":7.7,"label":"High","version":"4.0","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","source":"GitHub_M"},"assigner":"GitHub_M","products":["nicolargo glances"],"affected":[{"vendor":"nicolargo","product":"glances","versions":[{"version":"< 4.5.4","status":"affected"}]}],"references":["https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh","https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9"],"weaknesses":["CWE-200","CWE-942","CWE-306"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/34xxx/CVE-2026-34839.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34839","state":"PUBLISHED","datePublished":"2026-04-20T23:09:02.551Z","dateUpdated":"2026-04-21T19:37:42.399Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-30T20:52:53.284Z"},"containers":{"cna":{"title":"Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS","descriptions":[{"lang":"en","value":"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":[{"vendor":"nicolargo","product":"glances","versions":[{"version":"< 4.5.4","status":"affected"}]}],"references":[{"url":"https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh","name":"https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9","name":"https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":7.7,"baseSeverity":"HIGH","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-200","lang":"en","description":"CWE-200: Exposure of Sensitive Information to an Unauthorized Actor","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-942","lang":"en","description":"CWE-942: Permissive Cross-domain Policy with Untrusted Domains","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-306","lang":"en","description":"CWE-306: Missing Authentication for Critical Function","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-20T23:09:02.551Z"},"source":{"advisory":"GHSA-gfc2-9qmw-w7vh","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-21T19:37:18.710681Z","id":"CVE-2026-34839","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-21T19:37:42.399Z"}}]}}}