CVE-2026-27145MEDIUMCVSS 6.5

CVE-2026-27145

Published Jun 2, 2026·Updated Jul 2, 2026

Description

(*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject Alternative Name (SAN) entries. This caused strings.Split(host, ".") to execute repeatedly on the same input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before building the certificate chain, this overhead occurred even for untrusted certificates.

Public Exploits & PoCs1 found

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

References

View on NVD Search GitHub Search Google

Get alerted for CVEs like this

Register your stack and get notified within minutes when a matching CVE drops.

Start monitoring free