CVE-2026-39821 Affecting golang-docs package, versions <0:1.26.5-1.0.1.el9_8


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.48% (38th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ORACLE9-GOLANGDOCS-17951184
  • published11 Jul 2026
  • disclosed22 May 2026

Introduced: 22 May 2026

CVE-2026-39821  (opens in a new tab)

How to fix?

Upgrade Oracle:9 golang-docs to version 0:1.26.5-1.0.1.el9_8 or higher.
This issue was patched in ELSA-2026-37435.

NVD Description

Note: Versions mentioned in the description apply only to the upstream golang-docs package and not the golang-docs package as distributed by Oracle. See How to fix? for Oracle:9 relevant fixed versions and status.

The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode("xn--example-.com") incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".

CVSS Base Scores

version 3.1