GO-2026-5037

Inefficient candidate hostname parsing in crypto/x509

En bref

Publiée
Mise à jour
CVE
CVE-2026-27145
Alias
BIT-golang-2026-27145

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.

Paquets affectés

PaquetVersions
Go · stdlibintroduced 0, fixed 1.25.11, introduced 1.26.0-0, fixed 1.26.4

Références

Sources

SourceLicence
OSV.devCC-BY 4.0 — Go Vulnerability Database