CVE-2026-109383

CVE Details

Release Date:	2026-10-15
Impact:	Important	What is this?

Description

undici is an HTTP client library for Node.js. In versions 4.0.0 through 6.29.0, 7.0.0 through 7.30.0, and 8.0.0 through 8.12.1, its Agent dispatcher passes its constructor options through a JSON-based deep clone before forwarding them to each per-origin pool, and because JSON cannot represent functions, a caller-supplied tls option containing a checkServerIdentity callback is silently dropped before it reaches the TLS layer. As a result, a TLS peer whose certificate a custom checkServerIdentity was written to reject, but which passes Node's default hostname and chain checks, is silently accepted. Because Agent is the default dispatcher behind request, fetch, and setGlobalDispatcher, this affects the path most applications use, and EnvHttpProxyAgent is affected on its direct and no-proxy routes as well, while only applications that pass a function-valued tls option such as a custom checkServerIdentity for certificate or public-key pinning are at risk. The issue is fixed in undici 6.29.1, 7.30.1, and 8.12.2, which preserve the tls option outside the JSON clone so custom verification callbacks are forwarded unchanged, and users should upgrade to one of those versions or later. As a workaround, pass the TLS options through connect instead of tls, or for proxied destinations use requestTls and proxyTls.

See more information about CVE-2026-109383 from MITRE CVE dictionary and NIST NVD

NOTE: The following CVSS metrics and score provided are preliminary and subject to review.

CVSS v3 metrics

Base Score:	7.4
Vector String:	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Version:	3.1
Attack Vector:	Network
Attack Complexity:	High
Privileges Required:	None
User Interaction:	None
Scope:	Unchanged
Confidentiality Impact:	High
Integrity Impact:	High
Availability Impact:	None

Errata information

Platform	Errata	Release Date
Oracle Linux version 10 (nodejs22)	ELSA-2026-96094	2026-11-09
Oracle Linux version 9 (nodejs)	ELSA-2026-96226	2026-11-09
Oracle Linux version 9 (nodejs-nodemon)	ELSA-2026-96226	2026-11-09
Oracle Linux version 9 (nodejs-packaging)	ELSA-2026-96226	2026-11-09