{"id":"CVE-2026-109869","state":"PUBLISHED","title":"undici vulnerable to Denial of Service via unhandled error on excessive content-encodings","description":"undici is an HTTP client library for Node.js. In versions 6.23.0 through 6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch() implementation crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses because of a content-encoding limit, but it created the internal response stream before that check and returned without attaching an error listener or aborting the request, so the early close surfaces a content-length mismatch on the orphaned stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection, resulting in a denial of service. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. There is no workaround.","publishedAt":"2026-10-15T18:08:31.243Z","updatedAt":"2026-10-16T20:06:00.782Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"openjs"},"assigner":"openjs","products":["undici undici"],"affected":[{"vendor":"undici","product":"undici","packageURL":"pkg:npm/undici","defaultStatus":"unaffected","versions":[{"version":"6.23.0","status":"affected","lessThan":"6.29.1","versionType":"semver"},{"version":"6.29.1","status":"unaffected","versionType":"semver"},{"version":"7.18.0","status":"affected","lessThan":"7.30.1","versionType":"semver"},{"version":"7.30.1","status":"unaffected","versionType":"semver"},{"version":"8.0.0","status":"affected","lessThan":"8.12.2","versionType":"semver"},{"version":"8.12.2","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/nodejs/undici/security/advisories/GHSA-xjj6-f33q-929c","https://cna.openjsf.org/security-advisories.html"],"weaknesses":["CWE-248","CWE-459"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/109xxx/CVE-2026-109869.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-109869","state":"PUBLISHED","datePublished":"2026-10-15T18:08:31.243Z","dateUpdated":"2026-10-16T20:06:00.782Z","assignerShortName":"openjs","assignerOrgId":"ce714d77-add3-4f53-aff5-83d477b104bb","dateReserved":"2026-10-13T08:52:10.454Z"},"containers":{"cna":{"title":"undici vulnerable to Denial of Service via unhandled error on excessive content-encodings","descriptions":[{"lang":"en","value":"undici is an HTTP client library for Node.js. In versions 6.23.0 through 6.29.0, 7.18.0 through 7.30.0, and 8.0.0 through 8.12.1, its fetch() implementation crashes the Node.js process when a malicious server returns a response with more than five content codings and closes the connection before sending the body. undici rejects such responses because of a content-encoding limit, but it created the internal response stream before that check and returned without attaching an error listener or aborting the request, so the early close surfaces a content-length mismatch on the orphaned stream, which Node.js treats as an unhandled error and terminates the process. A remote, unauthenticated server can trigger this with a single response, even when the application correctly catches the fetch() rejection, resulting in a denial of service. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, and users should upgrade to one of those versions or later. There is no workaround."}],"affected":[{"vendor":"undici","product":"undici","packageURL":"pkg:npm/undici","defaultStatus":"unaffected","versions":[{"version":"6.23.0","status":"affected","lessThan":"6.29.1","versionType":"semver"},{"version":"6.29.1","status":"unaffected","versionType":"semver"},{"version":"7.18.0","status":"affected","lessThan":"7.30.1","versionType":"semver"},{"version":"7.30.1","status":"unaffected","versionType":"semver"},{"version":"8.0.0","status":"affected","lessThan":"8.12.2","versionType":"semver"},{"version":"8.12.2","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/nodejs/undici/security/advisories/GHSA-xjj6-f33q-929c"},{"url":"https://cna.openjsf.org/security-advisories.html"}],"metrics":[{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-248","lang":"en","description":"CWE-248: Uncaught Exception","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-459","lang":"en","description":"CWE-459: Incomplete Cleanup","type":"CWE"}]}],"providerMetadata":{"shortName":"openjs","orgId":"ce714d77-add3-4f53-aff5-83d477b104bb","dateUpdated":"2026-10-15T18:08:31.243Z"},"credits":[{"lang":"en","type":"reporter","value":"hanityx"},{"lang":"en","type":"remediation developer","value":"mcollina"},{"lang":"en","type":"remediation reviewer","value":"UlisesGascon"}],"x_generator":{"engine":"cve-kit 1.0.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-16T20:05:44.033842Z","id":"CVE-2026-109869","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-16T20:06:00.782Z"}}]}}}