Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-34839
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 03:15 UTC · Revision 1
Source evidence
Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
core-osv · Original sourcePublished 20 Apr 2026, 23:09 UTC
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.
osv:CVE-2026-34839
Complete source record
{
"id": "cf50fa419a51f19da5f38da917ff7a79c4879f9f0ab51f2eb11ff57d3571a502",
"url": "https://osv.dev/vulnerability/CVE-2026-34839",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS",
"summary": "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.",
"evidence": "osv:CVE-2026-34839",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-34839",
"aliases": [
"CVE-2026-34839",
"GHSA-gfc2-9qmw-w7vh",
"PYSEC-2026-2175"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "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"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/nicolargo/glances",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "05ff62d883d690809509517dec62684e6c4590d4"
},
{
"fixed": "fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:nicolargo:glances:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "4.5.4"
}
],
"source": "CPE_RANGE"
},
{
"range": [
{
"fixed": "fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
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"v4.5.2",
"v4.5.1",
"v4.5.0.5",
"v4.5.0.4",
"v4.5.0.3",
"v4.5.0.2",
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"v4.5.0",
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"v4.4.0",
"v4.3.3",
"v4.3.2",
"v4.3.1",
"v4.3.0.8",
"v4.3.0.7",
"v4.3.0.6",
"v4.3.0.3",
"v4.3.0.2",
"v4.3.0.1",
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"v3.1.3",
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"v3.1.1",
"v3.1.0",
"v3.0",
"v2.11",
"v2.10",
"v2.9.1",
"v2.9.0",
"v2.8.8",
"v2.8.7",
"v2.8.6",
"v2.8.5",
"v2.8.4",
"v2.8.3",
"v2.8.2",
"v2.8.1",
"v2.8",
"v2.7.1",
"v2.7",
"v2.7_RC1",
"v2.5.1",
"v2.5",
"v2.4.2",
"v2.4.1",
"v2.3",
"v2.2",
"v1.7.3",
"v1.7.2",
"v1.7.1",
"v1.7",
"v1.6.1",
"v1.6",
"v1.5.2",
"v1.5.1",
"v1.5",
"v1.4.2.1",
"v1.4.2",
"v1.4.1.1",
"v1.4.1",
"v1.4",
"v1.3.7",
"v1.3.6",
"v1.3.5",
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"v1.3.1",
"v1.3",
"v1.2",
"v1.1.3",
"v1.1.2",
"v1.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-34839.json"
}
}
],
"modified": "2026-10-28T02:30:32.729527242Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34839.json",
"https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh",
"https://nvd.nist.gov/vuln/detail/CVE-2026-34839",
"https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9"
],
"provider_metadata": {
"cwe_ids": [
"CWE-200",
"CWE-306",
"CWE-942"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34839.json"
}
},
"related_cves": [
{
"value": "CVE-2026-34839",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 499861,
"published_at": "2026-04-20T23:09:02.551+00:00"
}