RHSA-2026:37435HighCVSS 8.2

Red Hat Security Advisory: golang security, bug fix, and enhancement update

Published
July 9, 2026
Last Modified
September 6, 2026

🔗 CVE IDs covered (3)

CVE-2026-39822 →CVE-2026-42505 →CVE-2026-39821 →

📋 Description

CVE-2026-39821 — golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing CVE-2026-39822 — golang: Go os.Root: Symlink following vulnerability allows directory traversal CVE-2026-42505 — crypto/tls: golang: Go crypto/tls: Information disclosure in Encrypted Client Hello

🎯 Affected products22

  • Red Hat Enterprise Linux AppStream (v. 9)
  • go-toolset-0:1.26.5-1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • go-toolset-0:1.26.5-1.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • go-toolset-0:1.26.5-1.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • go-toolset-0:1.26.5-1.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-0:1.26.5-1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-0:1.26.5-1.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-0:1.26.5-1.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-0:1.26.5-1.el9_8.src as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-0:1.26.5-1.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-bin-0:1.26.5-1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-bin-0:1.26.5-1.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-bin-0:1.26.5-1.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-bin-0:1.26.5-1.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-docs-0:1.26.5-1.el9_8.noarch as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-misc-0:1.26.5-1.el9_8.noarch as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-race-0:1.26.5-1.el9_8.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-race-0:1.26.5-1.el9_8.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-race-0:1.26.5-1.el9_8.s390x as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-race-0:1.26.5-1.el9_8.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-src-0:1.26.5-1.el9_8.noarch as a component of Red Hat Enterprise Linux AppStream (v. 9)
  • golang-tests-0:1.26.5-1.el9_8.noarch as a component of Red Hat Enterprise Linux AppStream (v. 9)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Upgrade to a fixed golang.org/x/net release that includes the idna correction, via updated golang or dependent package rebuilds. Workaround: There is no mitigation for this issue other than updating the Go toolchain to Go 1.25.12 or Go 1.26.5. Programs compiled with Go >= 1.24 that do not use the os.Root API are not affected by this vulnerability. The os.Root API was introduced in Go 1.24. Go versions prior to 1.24 are not affected. This issue is fixed in Go 1.25.12 and Go 1.26.5. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

🔗 References (6)