RHSA-2026:57649: Important: golang security update

Published Aug 20, 2026
·
Updated

Important: golang security update

Other sources

The golang packages provide the Go programming language compiler.Security Fix(es): net/mail: golang: net/mail: Denial of Service via pathological email address parsing (CVE-2026-42499) cmd/go: golang: Go command (cmd/go): Integrity bypass due to checksum validation flaw via malicious module proxy (CVE-2026-42501) html/template: golang: Go html/template: Cross-Site Scripting via improper URL escaping in meta tag content (CVE-2026-39823) cmd/go: golang: Go 'go bug' command: Arbitrary file overwrite via symlink attack (CVE-2026-39819) net/http/internal/http2: golang: golang.org/x/net: Go HTTP/2: Denial of Service via malformed SETTINGSMAXFRAMESIZE frame (CVE-2026-33814) net/mail: golang: Go net/mail: Denial of Service via crafted email inputs (CVE-2026-39820) net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME (CVE-2026-33811) net/http/httputil: golang: net/http/httputil: ReverseProxy forwards hidden query parameters, potentially bypassing security controls (CVE-2026-39825) cmd/go: golang: Go tool pack: Arbitrary file write via malicious archive extraction (CVE-2026-39817) html/template: golang: html/template: Cross-site scripting due to incorrect script tag escaping (CVE-2026-39826) golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821) net/textproto: golang: Golang net/textproto: Misleading error messages via input injection (CVE-2026-42507) crypto/x509: golang: golang crypto/x509: Denial of Service via excessive processing of DNS SAN entries (CVE-2026-27145) golang: Go os.Root: Symlink following vulnerability allows directory traversal (CVE-2026-39822) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Red Hat

Affected Software

29 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle
Red Hat Red Hat Enterprise Linux for ARM 64 - 4 years of updates
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle
Red Hat Red Hat Enterprise Linux Server - AUS
Red Hat Red Hat Enterprise Linux for IBM z Systems - 4 years of updates
redhat/golang<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/go-toolset<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-bin<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-docs<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-misc<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-race<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-src<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-tests<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/go-toolset<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-bin<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-race<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/go-toolset<1.26.5-1.el9_4.aa
1.26.5-1.el9_4.aa
redhat/golang<1.26.5-1.el9_4.aa
1.26.5-1.el9_4.aa
redhat/golang-bin<1.26.5-1.el9_4.aa
1.26.5-1.el9_4.aa
redhat/golang-race<1.26.5-1.el9_4.aa
1.26.5-1.el9_4.aa
redhat/go-toolset<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-bin<1.26.5-1.el9_4
1.26.5-1.el9_4
redhat/golang-race<1.26.5-1.el9_4
1.26.5-1.el9_4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/golang to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  2. Upgrade

    Upgrade redhat/go-toolset to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  3. Upgrade

    Upgrade redhat/golang-bin to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  4. Upgrade

    Upgrade redhat/golang-docs to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  5. Upgrade

    Upgrade redhat/golang-misc to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  6. Upgrade

    Upgrade redhat/golang-race to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  7. Upgrade

    Upgrade redhat/golang-src to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  8. Upgrade

    Upgrade redhat/golang-tests to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4
  9. Upgrade

    Upgrade redhat/go-toolset to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4.aa
  10. Upgrade

    Upgrade redhat/golang to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4.aa
  11. Upgrade

    Upgrade redhat/golang-bin to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4.aa
  12. Upgrade

    Upgrade redhat/golang-race to a version that resolves this vulnerability.

    Fixed in 1.26.5-1.el9_4.aa

Event History

Aug 20, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·06:14 PM
Data Sourced
via Red Hat·06:14 PM
Severity

Frequently Asked Questions

1

Which deployments should be prioritized for this update?

Prioritize systems using Red Hat golang, go-toolset, golang-bin, or golang-race packages, particularly where Go applications parse email, serve HTTP/2, use reverse proxies, render HTML templates, perform CNAME lookups, or retrieve modules through a module proxy. The advisory also applies to the listed Red Hat Enterprise Linux Update Services for SAP Solutions and Extended Life Cycle offerings on x86_64, ARM 64, and Power LE.

2

What attacker-controlled inputs or conditions are relevant?

Several issues require crafted network or application inputs, including pathological email addresses, malformed HTTP/2 SETTINGS_MAX_FRAME_SIZE frames, long CNAME responses, and hidden query parameters sent through a ReverseProxy. Other issues involve a malicious module proxy, a malicious archive, or symlink manipulation affecting Go tooling commands.

3

Are fixed package versions or configuration workarounds provided?

No fixed package versions, default-configuration status, detection methods, or interim mitigations are included in the provided advisory data. The available remediation information is limited to the security update and the affected package families.

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