Medium (4.5) in nodejs undici. EPSS 0.8% chance of exploitation in the next 30 days. Fixed in undici 5.28.3, 6.6.1.
Undici is an HTTP/1.1 client, written from scratch for Node.js. Undici already cleared Authorization headers on cross-origin redirects, but did not clear `Proxy-Authentication` headers. This issue has been patched in versions 5.28.3 and 6.6.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Severity
CVSS 3.1
4.5 medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:N/A:N
EPSS
0.8% chance of exploitation in the next 30 days; higher than 55% of CVEs (scores of 2026-10-31)