Information disclosure in Go programming language - CVE-2026-42505

Vulnerability identifier: #VU140621

CSH Severity: Medium

CVSS v4 BT: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2026-42505

CWE-ID: CWE-200

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to improper information exposure in crypto/tls when performing handshakes that use Encrypted Client Hello. A remote attacker can observe network traffic to disclose sensitive information.

The issue can de-anonymize handshakes by exposing pre-shared key identities in the unencrypted client hello.

Go programming language
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Development Tools Module
openSUSE Leap
Anolis OS
go1.25-openssl-race
go1.25-openssl-debuginfo
go1.25-openssl-doc
go1.25-openssl
go1.25-race
go1.25
go1.25-doc
golang-misc
golang-src
golang-tests
golang-docs
golang-shared
golang-bin
golang
go1.26-openssl
go1.26-openssl-race
go1.26-openssl-doc
go1.26-race
go1.26-doc
go1.26

Install security update from vendor's website.

Go programming language - addressed in versions 1.25.12, 1.26.5, 1.27.0 rc.2
go1.25-openssl-race - addressed in versions 1.25.12-150000.1.27.1, 1.25.12-150600.13.21.1
go1.25-openssl-debuginfo - addressed in versions 1.25.12-150000.1.27.1, 1.25.12-150600.13.21.1
go1.25-openssl-doc - addressed in versions 1.25.12-150000.1.27.1, 1.25.12-150600.13.21.1
go1.25-openssl - addressed in versions 1.25.12-150000.1.27.1, 1.25.12-150600.13.21.1
go1.25-race - update to 1.25.12-150000.1.44.1
go1.25 - update to 1.25.12-150000.1.44.1
go1.25-doc - update to 1.25.12-150000.1.44.1
golang-misc - update to 1.26.5-1
golang-src - update to 1.26.5-1
golang-tests - update to 1.26.5-1
golang-docs - update to 1.26.5-1
golang-shared - update to 1.26.5-1
golang-bin - update to 1.26.5-1
golang - update to 1.26.5-1
go1.26-openssl - addressed in versions 1.26.5-150000.1.12.1, 1.26.5-150600.13.9.1
go1.26-openssl-race - addressed in versions 1.26.5-150000.1.12.1, 1.26.5-150600.13.9.1
go1.26-openssl-doc - addressed in versions 1.26.5-150000.1.12.1, 1.26.5-150600.13.9.1
go1.26-race - update to 1.26.5-150000.1.18.1
go1.26-doc - update to 1.26.5-150000.1.18.1
go1.26 - update to 1.26.5-150000.1.18.1

• https://pkg.go.dev/vuln/GO-2026-5856
• https://go.dev/cl/775960

• Multiple vulnerabilities in Go programming language
• SUSE update for go1.25
• SUSE update for go1.26
• SUSE update for go1.25-openssl
• SUSE update for go1.26-openssl
• SUSE update for go1.26-openssl
• SUSE update for go1.25-openssl
• Anolis OS update for golang