CVE-2026-27145
MEDIUM EPSS 42.4%
Published Jun 2, 20264w ago · Modified Jun 17, 20261w ago
6.5 CVSS 3.1
Published Jun 2, 2026 4w ago
Last Modified Jun 17, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity Low
Availability High
Threat Intelligence
EPSS Exploit Probability
42.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
References 4
- go.dev https://go.dev/cl/783621
- go.dev https://go.dev/issue/79694
- groups.google.com https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw
- pkg.go.dev https://pkg.go.dev/vuln/GO-2026-5037
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.