CVE catalog

CVE-2026-1527

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate th

[CVE catalog]

Severity: Medium · CVSS 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
Published: Mar 12, 2026, 8:17:18 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.28% · Oct 25, 2026

ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch) The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters: // lib/dispatcher/client-h1.js:1121 if (upgrade) { header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n` }

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`	not affected
Debian	node-undici	bookworm-security	`5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3`	not affected
Npm	undici	Not reported	`6.24.0`	fixed
Npm	undici	Not reported	`7.24.0`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	node-undici	source	sid	`7.24.5+dfsg+~cs3.2.0-1`	not yet assigned	Not reported	[1130882]
Debian	node-undici	source	forky	`7.24.5+dfsg+~cs3.2.0-1`	not yet assigned	Not reported	[1130882]
Debian	node-undici	source	trixie	`(unfixed)`	not yet assigned	Not reported	[1130882]
Debian	node-undici	source	bookworm	`Not affected`	unimportant	Not reported	[1130882]
Npm	undici	npm	Not reported	`6.24.0`	Not reported	Not reported	Not reported
Npm	undici	npm	Not reported	`7.24.0`	Not reported	Not reported	Not reported

[Debian bug #1130882]

Notes

[trixie] node-undici: Minor issue

OpenFactory catalog packages

[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

[Debian 12 (Bookworm)]

[node-llhttp]Not affected
Source package: [node-undici]
Details (4)
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Not affected
  nvd · node-undici · debian · bookworm
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Not affected
  nvd · node-undici · debian · bookworm
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Not affected
  nvd · node-undici · debian · bookworm
- 8.1.0~5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Not affected
  nvd · node-undici · debian · bookworm
[node-undici]Not affected
Details (4)
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Not affected
  nvd · node-undici · debian · bookworm
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4 · all · bookworm
  Not affected
  nvd · node-undici · debian · bookworm
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Not affected
  nvd · node-undici · debian · bookworm
- 5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3 · all · bookworm-security
  Not affected
  nvd · node-undici · debian · bookworm

Observed: Oct 24, 2026, 12:37:12 AM 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]