CVE-2026-42505 json
Invoking Encrypted Client Hello privacy leak in crypto/tls
published 2026-07-07 4 mo ago modified 2026-10-25 15 d ago also BIT-golang-2026-42505 , EUVD-2026-42317 , GO-2026-5856
- cvss
- 5.3
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 32%
- public exploits
- 0
- none known
Summary
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
Patch / fix
- bitnami golang 1.25.12, 1.26.5, 1.27.0
- go stdlib 1.25.12, 1.26.5, 1.27.0-rc.2
- Go standard library crypto/tls 1.25.12, 1.26.5, 1.27.0-rc.2
- golang-1.26 Debian 14 1.26.5-1
- golang-1.27 Debian 14 1.27~rc2-1
debian advisories DEBIAN-CVE-2026-42505
- git-lfs RHEL 9 3.7.1-4.el9_8.3
- golang1.25 hummingbird 1 1.25.12-0.1.hum1
- golang1.25-bin hummingbird 1 1.25.12-0.1.hum1
- golang1.25-src hummingbird 1 1.25.12-0.1.hum1
- golang1.25-misc hummingbird 1 1.25.12-0.1.hum1
- golang1.25-tests hummingbird 1 1.25.12-0.1.hum1
- golang1.26 hummingbird 1 1.26.5-0.1.hum1
- golang1.26-bin hummingbird 1 1.26.5-0.1.hum1
red hat advisories RHSA-2026:66364RHSA-2026:36510RHSA-2026:36477RHSA-2026:38995RHSA-2026:37435RHSA-2026:37436
- go1.25-openssl SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 1.25.12-150600.13.21.1
- go1.26-openssl SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 1.26.5-150600.13.9.1
- go1.26-openssl SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 1.26.5-150000.1.12.1
- go1.25-openssl SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 1.25.12-150000.1.27.1
- go1.26 SLES for SAP applications 16.0, SLES 16.0 1.26.5-160000.1.1
- go1.25 SLES for SAP applications 16.0, SLES 16.0 1.25.12-160000.1.1
- go1.26-openssl SLES for SAP applications 16.0, SLES 16.0 1.26.5-160000.1.1
- go1.25-openssl SLES for SAP applications 16.0, SLES 16.0 1.25.12-160000.1.1
suse advisories SUSE-SU-2026:3151-1SUSE-SU-2026:3102-1SUSE-SU-2026:3047-1SUSE-SU-2026:3046-1SUSE-SU-2026:22656-1SUSE-SU-2026:22643-1
- go-passbolt-cli openSUSE Tumbleweed 0.5.2-1.1
- tekton-cli openSUSE Tumbleweed 0.46.0-1.1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
- go1.26 openSUSE Leap 16.0 1.26.5-160000.1.1
- go1.25 openSUSE Leap 16.0 1.25.12-160000.1.1
- go1.26-openssl openSUSE Leap 16.0 1.26.5-160000.1.1
- go1.25-openssl openSUSE Leap 16.0 1.25.12-160000.1.1
- go1.26 openSUSE Tumbleweed 1.26.5-1.1
opensuse advisories openSUSE-SU-2026:11798-1openSUSE-SU-2026:11471-1openSUSE-SU-2026:21483-1openSUSE-SU-2026:21341-1openSUSE-SU-2026:21324-1openSUSE-SU-2026:21321-1
- git-lfs AlmaLinux 9 3.7.1-4.el9_8.3
- delve AlmaLinux 8 1.26.1-1.module_el8.10.0+4223+bd807c2e
- golang AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
- go-toolset AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
- golang-bin AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
- golang-src AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
- golang-misc AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
- golang-race AlmaLinux 8 1.26.5-1.module_el8.10.0+4223+bd807c2e
almalinux advisories ALSA-2026:66364ALSA-2026:38995ALSA-2026:37435ALSA-2026:37436
- go Alpine 3.24 1.26.8-r0
alpine advisories ALPINE-CVE-2026-42505
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- golang Azure Linux 3.0 1.25.12-1
- golang Azure Linux 3.0 1.26.5-1
azure linux advisories AZL-92306AZL-92312
Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT
- go.dev/cl/775960 patch
- go.dev/issue/79282 patch
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-42505 updated cvss 5.3
crypto/tls: golang: Go crypto/tls: Information disclosure in Encrypted Client Hello
-
Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 rhai/assisted-installer-rhel9 Red Hat Builds for Red Hat OpenShift openshift-builds/openshift-builds-waiters-rhel9 Red Hat cert-manager Operator for Red Hat OpenShift cert-manager/jetstack-cert-manager-rhel9 Red Hat Compliance Operator compliance/openshift-compliance-operator-bundle Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9-operator, openshift-sandboxed-containers/osc-monitor-rhel9 Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9affected: workaround, no fix available “Fix deferred”
+34 more productsfewer
Red Hat Custom Metric Autoscaler operator for Red Hat Openshift custom-metrics-autoscaler/custom-metrics-autoscaler-rhel9 Red Hat Deployment Validation Operator dvo/deployment-validation-rhel8-operator Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9 Red Hat Fence Agents Remediation Operator workload-availability/fence-agents-remediation-rhel8-operator Red Hat File Integrity Operator compliance/openshift-compliance-operator-bundle Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9-operator Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/eventrouter-rhel9 Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel8, lvms4/topolvm-rhel9, lvms4/lvms-rhel9-operator Red Hat Machine Deletion Remediation Operator workload-availability/machine-deletion-remediation-rhel8-operator Red Hat Migration Toolkit for Applications 8 mta/mta-cli-rhel9 Red Hat Migration Toolkit for Containers rhmtc/openshift-migration-registry-rhel8 Red Hat mirror registry for Red Hat OpenShift 2 openshift/mirror-registry-rhel8 Red Hat Multiarch Tuning Operator multiarch-tuning/multiarch-tuning-rhel9-operator Red Hat Multicluster Engine for Kubernetes multicluster-engine/maestro-rhel9, multicluster-engine/discovery-rhel9 Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-agent-rhel9 Red Hat Network Observability Operator network-observability/network-observability-cli-rhel9 Red Hat Node HealthCheck Operator node-healthcheck-operator-tech-preview/node-healthcheck-operator-rhel8 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel9 Red Hat OpenShift Developer Tools and Services helm 3.19.5-66.el9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-rhel9-operator Red Hat OpenShift Pipelines openshift-pipelines-client 1.15.3-11580.el8, openshift-pipelines/pipelines-scheduler-rhel9 Red Hat OpenShift Serverless kn-workflow-plugin 1.38.0-3.el9, openshift-serverless-clients 1.17.0-4.el9, openshift-serverless-1/logic-rhel9-operator, openshift-serverless-1/kn-plugin-event-sender-rhel9 Red Hat OpenShift Service Mesh 3 rh-osbs/openshift-golang-builder, openshift-service-mesh/kiali-rhel9 Red Hat OpenShift Source-to-Image (S2I) source-to-image/source-to-image-rhel8 Red Hat Power monitoring for Red Hat OpenShift openshift-power-monitoring/kepler-rhel9 Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel7-operator Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/subctl-rhel9, rhacm2/thanos-rhel9 Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-main-rhel9 Red Hat Ansible Automation Platform 2 receptor 1.6.5-1.el9ap, python-grpcio 1.58.3-1.el9ap, python3x-grpcio 1.58.3-1.el8ap, python3.11-grpcio 1.58.3-1.el9ap, python3.12-grpcio 1.71.2-1.el9ap, python3.11-galaxy-ng 4.11.5-1.el9ap, +7 more Red Hat Ceph Storage 5 rhceph/snmp-notifier-rhel8 Red Hat Ceph Storage 6 rhceph/snmp-notifier-rhel9 Red Hat Ceph Storage 7 rhceph/grafana-rhel9 Red Hat Ceph Storage 8 rhceph/grafana-rhel9 Red Hat Ceph Storage 9 rhceph/alloy-rhel10
36 more affected, 7 more fixed, 1 more not affected in the full advisory
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CISA ADP | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| CNA | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| OSV | 3.1 | 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | golang | <1.25.12 >=1.26.0-0, <1.26.5 >=1.27.0-0, <1.27.0 |
1.25.12 1.26.5 1.27.0 |
| go | stdlib | <1.25.12 >=1.26.0-0, <1.26.5 >=1.27.0-0, <1.27.0-rc.2 |
1.25.12 1.26.5 1.27.0-rc.2 |
Affected products
- Go standard library crypto/tls
Classification
- Weakness
-
- CWE-201 Insertion of Sensitive Information Into Sent Data
References
-
go.dev
/cl/775960
patch
-
go.dev
/issue/79282
issue-tracking, patch, report
-
groups.google.com
/g/golang-announce/c/OrmQE_Yp5Sc
mailing-list, release-notes, vendor-advisory, advisory, web
-
pkg.go.dev
/vuln/GO-2026-5856
vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-42505
web
Sources
- CVE List CVE-2026-42505
- NVD CVE-2026-42505
- OSV BIT-golang-2026-42505
- OSV GO-2026-5856
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.