CVE catalog

CVE-2026-16728

undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before

[CVE catalog]

Severity: Medium · CVSS 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Published: Jul 29, 2026, 8:59:02 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.29% · Oct 25, 2026

undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixed in undici 6.28.0, 7.29.0, and 8.9.0.

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`	fixed
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
Npm	undici	Not reported	`8.9.0`	fixed
Npm	undici	Not reported	`7.29.0`	fixed
Npm	undici	Not reported	`8.9.0`	fixed
Npm	undici	Not reported	`6.28.0`	fixed
Npm	undici	Not reported	`7.29.0`	fixed
Npm	undici	Not reported	`8.9.0`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	node-undici	source	sid	`8.9.0+dfsg+~cs3.2.0-1`	not yet assigned	Not reported	Not reported
Debian	node-undici	source	forky	`8.9.0+dfsg+~cs3.2.0-1`	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
Npm	undici	npm	Not reported	`8.9.0`	Not reported	GHSA-8XCM-R25X-G524	Not reported
Npm	undici	npm	Not reported	`7.29.0`	Not reported	Not reported	Not reported
Npm	undici	npm	Not reported	`8.9.0`	Not reported	Not reported	Not reported
Npm	undici	npm	Not reported	`6.28.0`	Not reported	Not reported	Not reported
Npm	undici	npm	Not reported	`7.29.0`	Not reported	Not reported	Not reported
Npm	undici	npm	Not reported	`8.9.0`	Not reported	Not reported	Not reported

Notes

[trixie] node-undici: Minor issue [bookworm] 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
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
[node-undici]Affected
Details (4)
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  nvd · node-undici · debian · bookworm; nvd · node-undici · debian · 12
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Affected
  nvd · node-undici · debian · bookworm; nvd · 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
  nvd · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · arm64 · trixie
  Affected
  nvd · 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
  nvd · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · arm64 · trixie
  Affected
  nvd · 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
  nvd · node-undici · debian · 13
- 9.2.1~7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  nvd · node-undici · debian · 13
[node-undici]Affected
Details (2)
- 7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  nvd · node-undici · debian · 13
- 7.3.0+dfsg1+~cs24.12.11-1 · all · trixie
  Affected
  nvd · node-undici · debian · 13

Observed: Oct 23, 2026, 9:43:10 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]