CVE-2026-27145

Name: CVE-2026-27145
Creator: NVD / NIST
Published: 2026-06-02T23:16:35.57+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.56%

Last modified Jun 17, 2026

This CVE is reserved or awaiting analysis. Details will appear once published by NVD.

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.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.56%

42.4th percentile

Probability of exploitation in the next 30 days. Learn more

References

Timeline

Published: Jun 2, 2026
Last Modified: Jun 17, 2026
Status: Awaiting Analysis

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Source: NVD / NIST