undici is vulnerable to CRLF Injection via upgrade option (undici undici)

CVE-2026-1527
MEDIUM 4.6

At a glance

Source
NVD
EPSS
EPSS 0.29 % · percentile 21 ()
State
PUBLISHED
Published
Updated
Assigner
openjs
NVD status
Analyzed

Description

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` }

Weaknesses (CWE)

  • CWE-93 — Improper Neutralization of CRLF Sequences

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 4.6CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:Nopenjs
CVSS 3.1MEDIUM 4.6CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:NNVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
undici · undiciaffected < 6.24.0; 7.0.0 < 7.24.0 ; unaffected 6.24.0: 7.24.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD