CVE catalog

CVE-2026-109383

node-undici: CVE-2026-109383

Severity: High · CVSS 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Published: Oct 15, 2026, 6:34:01 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.18% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	node-undici	sid	`8.12.2+dfsg+~cs3.2.3-2`	fixed
Debian	node-undici	forky	`8.10.2+dfsg+~cs3.2.2-1`	vulnerable
Debian	node-undici	trixie	`7.3.0+dfsg1+~cs24.12.11-1`	vulnerable
Debian	node-undici	bookworm	`5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4`	vulnerable
Debian	node-undici	bookworm-security	`5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3`	vulnerable
Cpe	undici	Not reported	`8.12.2`	fixed
Ubuntu	node-undici	24.04	`5.22.1+dfsg1+~cs20.10.10.2-1ubuntu1`	vulnerable
Ubuntu	node-undici	24.04	`5.26.3+dfsg1+~cs23.10.12-2`	vulnerable
Ubuntu	node-undici	26.10	`7.18.2+dfsg+~cs3.2.0-1build1`	vulnerable
Ubuntu	node-undici	26.10	`7.24.6+dfsg+~cs3.2.0-3`	vulnerable
Ubuntu	node-undici	26.10	`8.5.0+dfsg+~cs3.2.0-2`	vulnerable
Ubuntu	node-undici	26.10	`8.5.0+dfsg+~cs3.2.0-3`	vulnerable
Ubuntu	node-undici	26.10	`8.9.0+dfsg+~cs3.2.0-1`	vulnerable
Ubuntu	node-undici	26.04	`7.3.0+dfsg1+~cs24.12.11-2`	vulnerable
Ubuntu	node-undici	26.04	`7.16.0+dfsg+~cs3.2.0-2`	vulnerable
Ubuntu	node-undici	26.04	`7.18.2+dfsg+~cs3.2.0-1`	vulnerable
Ubuntu	node-undici	26.04	`7.18.2+dfsg+~cs3.2.0-1build1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	node-undici	source	sid	`8.12.2+dfsg+~cs3.2.3-1`	not yet assigned	Not reported	Not reported
Debian	node-undici	source	forky	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	node-undici	source	trixie	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	node-undici	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported
Cpe	undici	cpe	Not reported	`8.12.2`	Not reported	NVD-CVE-2026-109383	Not reported

Notes

[trixie] node-undici: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[node-llhttp]Affected
Source package: [node-undici]
Details (4)
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
[node-undici]Affected
Details (4)
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  dsa · node-undici · debian · bookworm; dsa · node-undici · debian · 12

[Debian 13 (Trixie)]

[libllhttp9.2]Affected
Source package: [node-undici]
Details (2)
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · amd64 · trixie
  Affected
  dsa · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · arm64 · trixie
  Affected
  dsa · node-undici · debian · 13
[libllhttp-dev]Affected
Source package: [node-undici]
Details (2)
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · amd64 · trixie
  Affected
  dsa · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · arm64 · trixie
  Affected
  dsa · node-undici · debian · 13
[node-llhttp]Affected
Source package: [node-undici]
Details (2)
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  dsa · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  dsa · node-undici · debian · 13
[node-undici]Affected
Details (2)
- 7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  dsa · node-undici · debian · 13
- 7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  dsa · node-undici · debian · 13

Observed: Oct 25, 2026, 6:48:18 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]