{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-1527", "assignerOrgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "state": "PUBLISHED", "assignerShortName": "openjs", "dateReserved": "2026-01-28T12:05:08.491Z", "datePublished": "2026-03-12T20:17:18.984Z", "dateUpdated": "2026-03-12T20:17:18.984Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "ce714d77-add3-4f53-aff5-83d477b104bb", "shortName": "openjs", "dateUpdated": "2026-03-12T20:17:18.984Z"}, "title": "undici is vulnerable to CRLF Injection via upgrade option", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-93", "description": "CWE-93 Improper neutralization of CRLF sequences ('CRLF injection')", "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": "ImpactWhen an application passes user-controlled input to the\u00a0upgrade\u00a0option of\u00a0client.request(), an attacker can inject CRLF sequences (\\r\\n) to:\n\n * Inject arbitrary HTTP headers\n * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)\nThe vulnerability exists because undici writes the\u00a0upgrade\u00a0value directly to the socket without validating for invalid header characters:\n\n// lib/dispatcher/client-h1.js:1121\nif (upgrade) {\n header += `connection: upgrade\\r\\nupgrade: ${upgrade}\\r\\n`\n}", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<h3>Impact</h3><p>When an application passes user-controlled input to the&nbsp;<code>upgrade</code>&nbsp;option of&nbsp;<code>client.request()</code>, an attacker can inject CRLF sequences (<code>\\r\\n</code>) to:</p><ol><li>Inject arbitrary HTTP headers</li><li>Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)</li></ol><p>The vulnerability exists because undici writes the&nbsp;<code>upgrade</code>&nbsp;value directly to the socket without validating for invalid header characters:</p><div><pre>// lib/dispatcher/client-h1.js:1121\nif (upgrade) {\n header += `connection: upgrade\\r\\nupgrade: ${upgrade}\\r\\n`\n}</pre></div>"}]}], "references": [{"url": "https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq"}, {"url": "https://hackerone.com/reports/3487198"}, {"url": "https://cna.openjsf.org/security-advisories.html"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE", "baseSeverity": "MEDIUM", "baseScore": 4.6, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N"}}], "credits": [{"lang": "en", "value": "Matteo Collina", "type": "remediation developer"}, {"lang": "en", "value": "Ulises Gasc\u00f3n", "type": "remediation developer"}, {"lang": "en", "value": "Raul Vega del Valle", "type": "analyst"}], "source": {"advisory": "GHSA-4992-7rv2-5pvq", "discovery": "EXTERNAL"}, "x_generator": {"engine": "Vulnogram 1.0.0"}}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "ImpactWhen an application passes user-controlled input to the\u00a0upgrade\u00a0option of\u00a0client.request(), an attacker can inject CRLF sequences (\\r\\n) to:\n\n * Inject arbitrary HTTP headers\n * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)\nThe vulnerability exists because undici writes the\u00a0upgrade\u00a0value directly to the socket without validating for invalid header characters:\n\n// lib/dispatcher/client-h1.js:1121\nif (upgrade) {\n header += `connection: upgrade\\r\\nupgrade: ${upgrade}\\r\\n`\n}"}], "id": "CVE-2026-1527", "lastModified": "2026-03-12T21:16:25.137", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 4.6, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.1, "impactScore": 2.5, "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}, "published": "2026-03-12T21:16:25.137", "references": [{"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://cna.openjsf.org/security-advisories.html"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq"}, {"source": "ce714d77-add3-4f53-aff5-83d477b104bb", "url": "https://hackerone.com/reports/3487198"}], "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-93"}], "source": "ce714d77-add3-4f53-aff5-83d477b104bb", "type": "Secondary"}]}

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