CVE-2026-27145mediumCWE-606

CVE-2026-27145: fallo de gravedad media en Go standard library crypto/x509

Inefficient candidate hostname parsing in crypto/x509

Publicada el 02 jun 2026 · Actualizada el 18 sep 2026

33Vexday Risk Score

Sin señal de explotación. Ella tiene prueba de concepto pública.

ssvc Attendcvss 6.5epss 0.6%

de la publicación al arma1 días

Publicada en NVD2 jun

1ª PoC+1d

probabilidad de explotación

0.6%top 53% de las CVE

explotación observada

noninguna fuente lo reporta

1 exploit(s) público(s)

(*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.

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

Productos afectados

Go standard library · crypto/x509

PoCs públicas encontradas — 1

githubgithub.com/HORKimhab/CVE-2026-27145★ 0

⚠ Recursos públicos, para evaluar la exposición de sistemas que controlas o estás autorizado a probar. Prueba solo con autorización.

CVEs relacionadas — Go standard library crypto/x509

En el mismo producto, de las más peligrosas a las menos.

CVE-2024-24783MEDIUMVerify panics on certificates with an unknown public key algorithm in crypto/x509EPSS 0.7%CVE-2026-27137HIGHIncorrect enforcement of email constraints in crypto/x509EPSS 0.6%CVE-2026-32280HIGHUnexpected work during chain building in crypto/x509EPSS 0.6%CVE-2025-22865HIGHParsePKCS1PrivateKey panic with partial keys in crypto/x509EPSS 0.6%CVE-2024-45341MEDIUMUsage of IPv6 zone IDs can bypass URI name constraints in crypto/x509EPSS 0.5%CVE-2025-61729HIGHExcessive resource consumption when printing error string for host certificate validation in crypto/x509EPSS 0.5%

Referencias