CVE-2026-39836: Panic in Dial and LookupPort when handling NUL byte on Windows in net

High severity · published May 7, 2026

CVE-2026-39836

Panic in Dial and LookupPort when handling NUL byte on Windows in net

7.5

CVSS

0.6%

EPSS

On KEV

Description

The Dial and LookupPort functions panic on Windows when provided with an input containing a NUL (0).

CVSS vector

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

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

None

Integrity

None

Availability

High

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.6% · higher than 50% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

net · Go standard library

before 1.25.10; 1.26.0-0 before 1.26.3 · source: vendor

GO · Golang

before 1.25.10; 1.26.0 before 1.26.3 · source: NVD

Affected product

net

Go standard library

All net CVEs

References

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-39836

CVE.org

https://www.cve.org/CVERecord?id=CVE-2026-39836

Patch

https://go.dev/cl/775320

Issue Tracking

https://go.dev/issue/79006

Issue Tracking

https://groups.google.com/g/golang-announce/c/qcCIEXso47M

Vendor Advisory

https://pkg.go.dev/vuln/GO-2026-4971