BREW-GLANCES-CVE-2026-34839 (CVE-2026-34839)

Vulnerability from osv_homebrew – Published: 2026-08-13 16:51 – Updated: 2026-09-10 19:18 – Source website
VLAI
Summary
Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS
Details

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.

Severity
7.7 (High)
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
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "fix": "bump",
        "range_state": "fixed",
        "upstream_fixed_in": "4.5.4"
      },
      "package": {
        "ecosystem": "Homebrew",
        "name": "glances",
        "purl": "pkg:brew/glances"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.5.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "confidence": "high",
    "source": "matched",
    "strategy": "git",
    "upstream_evidence": [
      {
        "ecosystem": "GIT",
        "key": "https://github.com/nicolargo/glances",
        "name": "https://github.com/nicolargo/glances",
        "strategy": "git",
        "subject_version": "4.5.6"
      },
      {
        "ecosystem": "PyPI",
        "key": "pkg:pypi/glances@4.5.6",
        "name": "glances",
        "strategy": "registry",
        "subject_version": "4.5.6"
      },
      {
        "ecosystem": "Debian",
        "key": "Debian/glances",
        "name": "glances",
        "strategy": "distro"
      },
      {
        "ecosystem": "GIT",
        "key": "upstream:https://github.com/nicolargo/glances",
        "name": "https://github.com/nicolargo/glances",
        "strategy": "distro",
        "subject_version": "4.5.6"
      },
      {
        "ecosystem": "PyPI",
        "key": "upstream:pkg:pypi/glances@4.5.6",
        "name": "glances",
        "strategy": "distro",
        "subject_version": "4.5.6"
      },
      {
        "ecosystem": "Ubuntu",
        "key": "Ubuntu/glances",
        "name": "glances",
        "strategy": "distro"
      }
    ]
  },
  "details": "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\u2019s 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.",
  "id": "BREW-glances-CVE-2026-34839",
  "modified": "2026-09-10T19:18:35Z",
  "published": "2026-08-13T16:51:23Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34839.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/nicolargo/glances/security/advisories/GHSA-gfc2-9qmw-w7vh"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34839"
    },
    {
      "type": "FIX",
      "url": "https://github.com/nicolargo/glances/commit/fdfb977b1d91b5e410bc06c4e19f8bedb0005ce9"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Glances Vulnerable to Cross-Origin Information Disclosure via Unauthenticated REST API (/api/4) due to Permissive CORS",
  "upstream": [
    "CVE-2026-34839",
    "GHSA-gfc2-9qmw-w7vh",
    "PYSEC-2026-2175"
  ]
}



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