{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-2229", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-02-08T17:51:16.985Z", "datePublished": "2026-03-12T20:27:05.600Z", "dateUpdated": "2026-03-12T20:27:05.600Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-03-12T20:27:05.600Z"}, "title": "undici is vulnerable to Unhandled Exception in undici WebSocket Client Due to Invalid server_max_window_bits Validation", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-248", "description": "CWE-248 Uncaught exception", "type": "CWE"}]}, {"descriptions": [{"lang": "en", "cweId": "CWE-1284", "description": "CWE-1284 Improper validation of specified quantity in input", "type": "CWE"}]}], "affected": [{"vendor": "undici", "product": "undici", "collectionURL": "https://github.com/nodejs/undici/", "packageName": "undici", "repo": "https://github.com/nodejs/undici/", "versions": [{"status": "affected", "version": "< 6.24.0; 7.0.0 < 7.24.0"}, {"status": "unaffected", "version": "6.24.0: 7.24.0"}], "defaultStatus": "unaffected"}], "descriptions": [{"lang": "en", "value": "ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the\u00a0server_max_window_bits\u00a0parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range\u00a0server_max_window_bits\u00a0value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.\n\nThe vulnerability exists because:\n\n * The\u00a0isValidClientWindowBits()\u00a0function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15\n * The\u00a0createInflateRaw()\u00a0call is not wrapped in a try-catch block\n * The resulting exception propagates up through the call stack and crashes the Node.js process", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<h3><span>Impact</span></h3><p>The undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the&nbsp;<code>server_max_window_bits</code>&nbsp;parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range&nbsp;<code>server_max_window_bits</code>&nbsp;value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.</p><p>The vulnerability exists because:</p><ol><li>The&nbsp;<code>isValidClientWindowBits()</code>&nbsp;function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15</li><li>The&nbsp;<code>createInflateRaw()</code>&nbsp;call is not wrapped in a try-catch block</li><li>The resulting exception propagates up through the call stack and crashes the Node.js process</li></ol><br>"}]}], "references": [{"url": "https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8"}, {"url": "https://hackerone.com/reports/3487486"}, {"url": "https://cna.openjsf.org/security-advisories.html"}, {"url": "https://datatracker.ietf.org/doc/html/rfc7692"}, {"url": "https://nodejs.org/api/zlib.html#class-zlibinflateraw"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}], "credits": [{"lang": "en", "value": "Matteo Collina", "type": "remediation developer"}, {"lang": "en", "value": "Ulises Gasc\u00f3n", "type": "remediation reviewer"}, {"lang": "en", "value": "Rafael Gonzaga", "type": "remediation reviewer"}, {"lang": "en", "value": "Ethan Arrowood", "type": "remediation reviewer"}, {"lang": "en", "value": "Aisle Research", "type": "reporter"}], "source": {"advisory": "GHSA-v9p9-hfj2-hcw8", "discovery": "UNKNOWN"}, "x_generator": {"engine": "Vulnogram 1.0.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "ImpactThe undici WebSocket client is vulnerable to a denial-of-service attack due to improper validation of the\u00a0server_max_window_bits\u00a0parameter in the permessage-deflate extension. When a WebSocket client connects to a server, it automatically advertises support for permessage-deflate compression. A malicious server can respond with an out-of-range\u00a0server_max_window_bits\u00a0value (outside zlib's valid range of 8-15). When the server subsequently sends a compressed frame, the client attempts to create a zlib InflateRaw instance with the invalid windowBits value, causing a synchronous RangeError exception that is not caught, resulting in immediate process termination.\n\nThe vulnerability exists because:\n\n * The\u00a0isValidClientWindowBits()\u00a0function only validates that the value contains ASCII digits, not that it falls within the valid range 8-15\n * The\u00a0createInflateRaw()\u00a0call is not wrapped in a try-catch block\n * The resulting exception propagates up through the call stack and crashes the Node.js process"}], "id": "CVE-2026-2229", "lastModified": "2026-03-12T21:16:25.573", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-03-12T21:16:25.573", "references": [{"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://cna.openjsf.org/security-advisories.html"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://datatracker.ietf.org/doc/html/rfc7692"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://github.com/nodejs/undici/security/advisories/GHSA-v9p9-hfj2-hcw8"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://hackerone.com/reports/3487486"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://nodejs.org/api/zlib.html#class-zlibinflateraw"}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-248"}, {"lang": "en", "value": "CWE-1284"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

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