CVE-2026-27145Published

(*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 l…

Exact source revision recorded 25 Oct 2026 06:17:28 UTC. It does not establish the source's current position. Latest evidence.

Recorded JSON

nvd · CVE-2026-27145

Published

(*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.

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Awaiting Analysis

Weakness classifications: CWE-606

Original publisher date fields

published: 2026-06-02T23:16:35.570

lastModified: 2026-09-18T13:17:43.283

Source published: 2 Jun 2026 23:16:35 UTC
Source modified: 18 Sep 2026 13:17:43 UTC
Observed here: 25 Oct 2026 06:17:28 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0 · Secondary · 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H