Detections
Analytics

Golang 1.25.x < 1.25.13 / 1.26.x < 1.26.6 Multiple Vulnerabilities

critical Nessus Plugin ID 335411

Synopsis

An application installed on the remote host is affected by multiple vulnerabilities.

Description

The version of Golang running on the remote host is 1.25.x prior to 1.25.13, or 1.26.x prior to 1.26.6. It is, therefore, affected by multiple vulnerabilities in the standard library and the toolchain, as referenced in the golang-announce advisory.

 - The ToASCII and ToUnicode functions incorrectly accepted Punycode-encoded labels that decode to an ASCII-only label. This can lead to privilege escalation in programs using the idna package.
 (CVE-2026-39821)

 - Parsing an invalid SVCB or HTTPS RR can panic when the size of a parameter value overflows the message buffer in golang.org/x/net/dns/dnsmessage. (CVE-2026-46600)

 - When a server is configured to support unencrypted HTTP/2, it reads bytes from each new connection to check for the HTTP/2 client preface. Previously this was done with no timeout. ReadHeaderTimeout is now applied for this check. (CVE-2026-56853)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Golang Go version 1.25.13, 1.26.6, or later.

See Also

https://groups.google.com/g/golang-announce/c/8tdz5l-ccTs

http://www.nessus.org/u?3e20b36a

Plugin Details

Severity: Critical

ID: 335411

File Name: golang_1_25_13_1_26_6.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 8/14/2026

Updated: 8/14/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.81

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

CVSS Score Source: CVE-2026-39821

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Vulnerability Information

CPE: cpe:/a:golang:go

Required KB Items: installed_sw/Golang Go Programming Language

Patch Publication Date: 8/13/2026

Vulnerability Publication Date: 8/7/2026

Reference Information

CVE: CVE-2026-33818, CVE-2026-39821, CVE-2026-46600, CVE-2026-56853, CVE-2026-56858, CVE-2026-56859, CVE-2026-56860, CVE-2026-56862, CVE-2026-56864, CVE-2026-56865