Error Handling in Go programming language - CVE-2026-27138

Vulnerability identifier: #VU124116

CSH Severity: Medium

CVSS v4 BT: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2026-27138

CWE-ID: CWE-388

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service via application crash during X.509 certificate verification.

The vulnerability exists due to a panic in name constraint checking in crypto/x509 when processing a certificate chain containing a certificate with an empty DNS name and another certificate with excluded name constraints. A remote attacker can send a specially crafted certificate chain to trigger a panic during verification.

This issue only affects Go 1.26 and requires the certificate chain to chain to a trusted root. A trusted CA must issue the malformed certificate.

Go programming language
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Development Tools Module
openSUSE Leap
go1.26-openssl
go1.26-openssl-doc
go1.26-openssl-race
go1.26-race
go1.26-doc
go1.26
App Connect Enterprise Certified Container

Install security update from vendor's website.

Go programming language - update to 1.26.1
go1.26-openssl - addressed in versions 1.26.1-150000.1.3.1, 1.26.1-150600.13.3.1
go1.26-openssl-doc - addressed in versions 1.26.1-150000.1.3.1, 1.26.1-150600.13.3.1
go1.26-openssl-race - addressed in versions 1.26.1-150000.1.3.1, 1.26.1-150600.13.3.1
go1.26-race - update to 1.26.1-150000.1.6.1
go1.26-doc - update to 1.26.1-150000.1.6.1
go1.26 - update to 1.26.1-150000.1.6.1
App Connect Enterprise Certified Container - addressed in versions 12.0.22, 13.0.0

• https://groups.google.com/g/golang-announce/c/EdhZqrQ98hk
• https://go.dev/issue/77953

• Multiple vulnerabilities in Go programming language
• SUSE update for go1.26
• SUSE update for go1.26-openssl
• SUSE update for go1.26-openssl
• Multiple vulnerabilities in IBM App Connect Enterprise Certified