{"schema_version":"1.7.5","id":"GHSA-4992-7rv2-5pvq","published":"2026-03-13T20:41:26Z","modified":"2026-03-18T22:58:58.996775Z","aliases":["CVE-2026-1527"],"related":["CGA-474r-8wcx-87w5"],"summary":"Undici has CRLF Injection in undici via `upgrade` option","details":"### Impact\n\nWhen an application passes user-controlled input to the `upgrade` option of `client.request()`, an attacker can inject CRLF sequences (`\\r\\n`) to:\n\n1. Inject arbitrary HTTP headers\n2. Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch)\n\nThe vulnerability exists because undici writes the `upgrade` value directly to the socket without validating for invalid header characters:\n\n```javascript\n// lib/dispatcher/client-h1.js:1121\nif (upgrade) {\n  header += `connection: upgrade\\r\\nupgrade: ${upgrade}\\r\\n`\n}\n```\n\n### Patches\n\n Patched in the undici version v7.24.0 and v6.24.0. Users should upgrade to this version or later.\n\n### Workarounds\n\nSanitize the `upgrade` option string before passing to undici:\n\n```javascript\nfunction sanitizeUpgrade(value) {\n  if (/[\\r\\n]/.test(value)) {\n    throw new Error('Invalid upgrade value')\n  }\n  return value\n}\n\nclient.request({\n  upgrade: sanitizeUpgrade(userInput)\n})\n```","affected":[{"package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"6.24.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-4992-7rv2-5pvq/GHSA-4992-7rv2-5pvq.json"}},{"package":{"name":"undici","ecosystem":"npm","purl":"pkg:npm/undici"},"ranges":[{"type":"SEMVER","events":[{"introduced":"7.0.0"},{"fixed":"7.24.0"}]}],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-4992-7rv2-5pvq/GHSA-4992-7rv2-5pvq.json"}}],"references":[{"type":"WEB","url":"https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-1527"},{"type":"WEB","url":"https://hackerone.com/reports/3487198"},{"type":"WEB","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"PACKAGE","url":"https://github.com/nodejs/undici"}],"database_specific":{"cwe_ids":["CWE-93"],"github_reviewed":true,"github_reviewed_at":"2026-03-13T20:41:26Z","nvd_published_at":"2026-03-12T21:16:25Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N"}]}