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Fencer Vulns
high 7.5

CVE-2026-27137 json

Incorrect enforcement of email constraints in crypto/x509

published 2026-03-06 8 mo ago modified 2026-10-07 33 d ago also BIT-golang-2026-27137 , EUVD-2026-10085 , GO-2026-4599

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.7%
EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits
0
none known

Summary

When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.

Patch / fix

  • bitnami golang 1.26.1
  • go stdlib 1.26.1
  • Go standard library crypto/x509 1.26.1
  • Red Hat Red Hat Enterprise Linux 10 0:0.2.3-4.el10_1, 0:0.2.7-3.el10_2, 0:0.9.27-6.el10_2, 0:1.25.2-3.el10_1, 0:1.26.2-2.el10_2, 0:52.1-1.el10_2, 0:165.1-2.el10_2
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support 0:0.2.3-4.el10_0, 0:1.26.1-1.el10_0, 0:1.26.5-1.el10_0, 0:5.3.0-1.el10_0, 0:10.2.6-26.el10_0
  • Red Hat Red Hat Enterprise Linux 9 0:1.26.2-1.el9_8, 0:52.1-1.el9_8, 0:165.1-2.el9_8
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions 0:1.26.5-1.el9_2, 0:5.1.1-5.el9_2.2
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions 0:1.26.5-1.el9_4, 0:5.1.1-9.el9_4
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support 0:1.26.5-1.el9_6, 0:5.1.1-15.el9_6, 0:10.2.6-23.el9_6, 6:0.8.5-2.el9_6.2
  • Red Hat Red Hat OpenStack Platform 16.2 0:0.2.1-1.1.el8ost, 0:3.3.23-22.el8ost
  • Red Hat Red Hat OpenStack Platform 17.1 for RHEL 9 0:3.4.26-9.5.el9ost
  • Red Hat Red Hat OpenStack Services on OpenShift 18.0 0:0.1.1-18.0.20260602234716.a95ae05.el9ost
  • Red Hat RHEM 1.0 for RHEL 9 0:1.0.3-1.el9em
  • Red Hat RHEM 1.1 for RHEL 10 0:1.1.3-1.el10em
  • Red Hat RHEM 1.1 for RHEL 9 0:1.1.3-1.el9em
  • Red Hat Builds for Red Hat OpenShift 1.6.0 1774334066
  • Red Hat DevWorkspace Operator 0.4 1776457293
  • Red Hat Logging for Red Hat OpenShift 6 1781192891
  • Red Hat Logging for Red Hat OpenShift 6.2 1776800087
  • Red Hat Logging Subsystem for Red Hat OpenShift 6.4 1780051640
  • Red Hat Multicluster Global Hub 1.3.4 1779210675
  • Red Hat Multicluster Global Hub 1.4.5 1779838819
  • Red Hat Multicluster Global Hub 1.6.5 1780320809
  • Red Hat OpenShift API for Data Protection 1.4 1779809598
  • Red Hat OpenShift API for Data Protection 1.5 1779808027
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15 1774085848
  • Red Hat Red Hat Ansible Automation Platform 2.6 1777391542
  • Red Hat Red Hat Hardened Images 1.26.2-1.hum1
  • Red Hat Red Hat Lightspeed (formerly Insights) for Runtimes 1.0 1.0.2-1776288486
  • Red Hat Red Hat Migration Toolkit 1.8 1783914276
  • golang-1.26 Debian 14 1.26.1-1

debian advisories DEBIAN-CVE-2026-27137

  • etcd openstack 16.2 3.3.23-22.el8ost
  • erlang openstack 16.2 23.3.4.18-2.el8ost
  • erlang-ssl openstack 16.2 23.3.4.18-2.el8ost
  • erlang-asn1 openstack 16.2 23.3.4.18-2.el8ost
  • erlang-erts openstack 16.2 23.3.4.18-2.el8ost
  • erlang-hipe openstack 16.2 23.3.4.18-2.el8ost
  • erlang-sasl openstack 16.2 23.3.4.18-2.el8ost
  • erlang-snmp openstack 16.2 23.3.4.18-2.el8ost

red hat advisories RHSA-2026:76795RHSA-2026:76809RHSA-2026:67517RHSA-2026:67518RHSA-2026:67160RHSA-2026:67159

  • go1.26-openssl SLES for SAP applications 16.0, SLES 16.0 1.26.1-160000.1.1
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260317T205859-150000.1.152.1
  • go1.26-openssl SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 1.26.1-150000.1.3.1
  • go1.26-openssl SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Development Tools 15 SP7 +1 more 1.26.1-150600.13.3.1
  • go1.26 SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +9 more 1.26.1-150000.1.6.1

suse advisories SUSE-SU-2026:21195-1SUSE-SU-2026:1042-1SUSE-SU-2026:0993-1SUSE-SU-2026:0976-1SUSE-SU-2026:0876-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • kubelogin openSUSE Tumbleweed 0.2.18-1.1
  • go1.26-openssl openSUSE Leap 16.0 1.26.1-160000.1.1
  • go1.26 openSUSE Leap 16.0 1.26.1-160000.1.1
  • go1.26 openSUSE Tumbleweed 1.26.1-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:10909-1openSUSE-SU-2026:20537-1openSUSE-SU-2026:20342-1openSUSE-SU-2026:10299-1

  • golang AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • go-toolset AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang-bin AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang-src AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang-misc AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang-race AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang-tests AlmaLinux 10 1.26.2-2.el10_2.alma.1
  • golang AlmaLinux 9 1.26.2-1.el9_8

almalinux advisories ALSA-2026:19022ALSA-2026:19181ALSA-2026:8842

  • osbuild-composer Rocky Linux 9 165.1-2.el9_8.rocky.0.1
  • osbuild-composer Rocky Linux 10 165.1-2.el10_2.rocky.0.1
  • image-builder Rocky Linux 10 52.1-1.el10_2.rocky.0.1
  • image-builder Rocky Linux 9 52.1-1.el9_8
  • golang Rocky Linux 10 1.26.2-2.el10_2
  • golang Rocky Linux 9 1.26.2-1.el9_8
  • delve Rocky Linux 10 1.25.2-3.el10_1

rocky linux advisories RLSA-2026:22714RLSA-2026:22450RLSA-2026:22937RLSA-2026:23228RLSA-2026:19022RLSA-2026:19181

  • go Alpine 3.24, Alpine 3.23 1.25.8-r0
  • rclone Alpine 3.24 1.73.5-r0

alpine advisories ALPINE-CVE-2026-27137

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 1.26.1-1

azure linux advisories AZL-79628

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

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-2026-27137 updated cvss 7.5

crypto/x509: Incorrect enforcement of email constraints in crypto/x509

  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2 rhai/assisted-installer-rhel9
    affected: workaround, no fix available
  • Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9-operator, openshift-sandboxed-containers/osc-monitor-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat Cryostat 4 cryostat/cryostat-grafana-dashboard-rhel9 Red Hat Deployment Validation Operator dvo/deployment-validation-rhel8-operator Red Hat ExternalDNS Operator edo/external-dns-rhel8, edo/external-dns-rhel9 Red Hat Fence Agents Remediation Operator fence-agents-remediation-operator-container Red Hat Gatekeeper 3 gatekeeper/gatekeeper-rhel9-operator Red Hat Lightspeed Core lightspeed-core/rag-tool-cpu-rhel9
    affected: workaround, no fix available
  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/eventrouter-rhel9, openshift-logging/logging-loki-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel8, lvms4/topolvm-rhel9, lvms4/lvms-rhel9-operator Red Hat mirror registry for Red Hat OpenShift openshift/mirror-registry-rhel8 Red Hat OpenShift Developer Tools and Services helm, openshift-jenkins-2-container, ocp-tools-4/jenkins-agent-base-rhel9 Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-rhel9-operator Red Hat OpenShift Pipelines openshift-pipelines-client Red Hat OpenShift Serverless openshift-serverless-clients, openshift-serverless-1/kn-plugin-event-sender-rhel9
    +1 more products
    Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9
    affected: workaround, no fix available
  • Red Hat 3scale API Management Platform 2 3scale-amp26/operator, 3scale-amp26/3scale-operator, 3scale-amp2/3scale-rhel7-operator, 3scale-amp2/3scale-rhel9-operator
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat build of Apache Camel - HawtIO 4 hawtio-operator-container
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Podman Desktop rh-podman-desktop Red Hat Certification Program for Red Hat Enterprise Linux 9 redhat-certification-preflight Red Hat Connectivity Link 1 rhcl-1/coredns-rhel9
    affected: workaround, no fix available
show 12 more
  • Red Hat Developer Hub 1 rhdh/rhdh-rhel9-operator
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 conmon, golang, grafana, go-toolset, golang-bin, golang-src, +19 more Red Hat Enterprise Linux 9 runc, butane, conmon, podman, skopeo, buildah, +20 more Red Hat Enterprise Linux 10 butane, conmon, skopeo, grafana, ignition, yggdrasil, +6 more
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AI (RHEL AI) 3 golang Red Hat OpenShift Cluster Manager CLI ocm-cli-clients/ocm-cli-rhel9
    affected: workaround, no fix available
  • Red Hat OpenShift Container Platform 4 cri-o, conmon, conmon-rs, cri-tools, microshift, microshift-olm, +21 more
    affected: workaround, no fix available, no fix planned “Out of support scope”
  • Red Hat Openshift Data Foundation 4 odf4/cephcsi-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat OpenShift on AWS rosa Red Hat OpenStack Platform 16.2 golang-github-infrawatch-apputils Red Hat OpenStack Platform 18.0 rhoso-operators/sg-core-rhel9
    affected: workaround, no fix available
  • Red Hat Quay 3 quay/quay-rhel8
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Satellite 6 yggdrasil-worker-forwarder Red Hat Trusted Artifact Signer rhtas/ec-rhel9 Red Hat Trusted Profile Analyzer rhtpa/rhtpa-rhel10-operator
    affected: workaround, no fix available
  • Red Hat streams for Apache Kafka 3 golang-github-danielqsj-kafka_exporter 1.9.0-12.el9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Zero Trust Workload Identity Manager zero-trust-workload-identity-manager/spiffe-csi-driver-rhel9
    affected: workaround, no fix available
  • Red Hat Zero Trust Workload Identity Manager - Tech Preview zero-trust-workload-identity-manager/spiffe-spire-agent-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Builds for Red Hat OpenShift 1.6.0 openshift-builds 1774334066
    fixed: vendor fix RHSA-2026:5549

51 more fixed, 76 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
8 mo ago

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami golang
>=1.26.0-0, <1.26.1
1.26.1
go stdlib
>=1.26.0-0, <1.26.1
1.26.1

Affected products

  • Go standard library crypto/x509
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions
  • Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support
  • Red Hat Red Hat OpenStack Platform 16.2
  • Red Hat Red Hat OpenStack Platform 17.1 for RHEL 9
  • Red Hat Red Hat OpenStack Services on OpenShift 18.0
  • Red Hat RHEM 1.0 for RHEL 9
  • Red Hat RHEM 1.1 for RHEL 10
  • Red Hat RHEM 1.1 for RHEL 9
  • Red Hat Builds for Red Hat OpenShift 1.6.0
  • Red Hat DevWorkspace Operator 0.4
  • Red Hat Logging for Red Hat OpenShift 6
  • Red Hat Logging for Red Hat OpenShift 6.2
  • Red Hat Logging Subsystem for Red Hat OpenShift 6.4
  • Red Hat Multicluster Global Hub 1.3.4
  • Red Hat Multicluster Global Hub 1.4.5
  • Red Hat Multicluster Global Hub 1.6.5
  • Red Hat OpenShift API for Data Protection 1.4
  • Red Hat OpenShift API for Data Protection 1.5
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15
  • Red Hat Red Hat Ansible Automation Platform 2.6
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Lightspeed (formerly Insights) for Runtimes 1.0
  • Red Hat Red Hat Migration Toolkit 1.8
  • Red Hat Red Hat multicluster global hub 1.5.3
  • Red Hat Red Hat OpenShift AI 2.25
  • Red Hat Red Hat OpenShift Builds 1.7.3
  • Red Hat Red Hat OpenShift Dev Spaces 3.27
  • Red Hat Red Hat OpenShift distributed tracing 3.9.3
  • Red Hat Red Hat OpenShift GitOps 1.18
  • Red Hat Red Hat OpenShift GitOps 1.19
  • Red Hat Red Hat OpenShift GitOps 1.20
  • Red Hat Red Hat Quay 3.16
  • Red Hat Red Hat Satellite 6.18
  • Red Hat Red Hat Trusted Artifact Signer 1.3
  • Red Hat Red Hat Web Terminal 1.11
  • Red Hat Red Hat Web Terminal 1.12
  • Red Hat Red Hat Web Terminal 1.13
  • Red Hat Red Hat Web Terminal 1.14
  • Red Hat Red Hat Web Terminal 1.15
  • Red Hat Assisted Installer for Red Hat OpenShift Container Platform 2
  • Red Hat cert-manager Operator for Red Hat OpenShift
  • Red Hat Compliance Operator
  • Red Hat Confidential Compute Attestation
  • Red Hat Cryostat 4
  • Red Hat Custom Metric Autoscaler operator for Red Hat Openshift

Classification

Weakness
  • CWE-295 Improper Certificate Validation

References

Sources

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.