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.
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Fri, 16 Oct 2026 00:30:00 +0000
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Thu, 15 Oct 2026 18:30:00 +0000
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| 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. | |
| Title | undici vulnerable to Denial of Service via unhandled error on excessive content-encodings | |
| Weaknesses | CWE-248 CWE-459 |
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cvssV3_1
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Status: PUBLISHED
Assigner: openjs
Published:
Updated: 2026-10-15T18:08:31.243Z
Reserved: 2026-10-13T08:52:10.454Z
Link: CVE-2026-109869
No data.
Status : Awaiting Analysis
Published: 2026-10-15T19:17:21.770
Modified: 2026-10-15T20:38:04.303
Link: CVE-2026-109869
OpenCVE Enrichment
Updated: 2026-10-16T06:45:14Z