CVE-2026-39836 json
Panic in Dial and LookupPort when handling NUL byte on Windows in net
published 2026-05-07 6 mo ago modified 2026-10-26 13 d ago also BIT-golang-2026-39836 , EUVD-2026-28427 , GO-2026-4971
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
The Dial and LookupPort functions panic on Windows when provided with an input containing a NUL (0).
Patch / fix
- bitnami golang 1.25.10, 1.26.3
- go stdlib 1.25.10, 1.26.3
- Go standard library net 1.25.10, 1.26.3
- golang RHEL 9 1.26.3-1.el9_8
- go-toolset RHEL 9 1.26.3-1.el9_8
- golang-bin RHEL 9 1.26.3-1.el9_8
- golang-src RHEL 9 1.26.3-1.el9_8
- golang-misc RHEL 9 1.26.3-1.el9_8
- golang-race RHEL 9 1.26.3-1.el9_8
- golang-tests RHEL 9 1.26.3-1.el9_8
- delve RHEL 8 1.25.2-1.module+el8.10.0+23746+9db33b5e
red hat advisories RHSA-2026:22121RHSA-2026:22112RHSA-2026:22120RHSA-2026:23264RHSA-2026:23262
- go1.25-openssl 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 1.26.4-160000.1.1
suse advisories SUSE-SU-2026:22638-1SUSE-SU-2026:22572-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
- go1.25-openssl openSUSE Leap 16.0 1.25.12-160000.1.1
- go1.26-openssl openSUSE Leap 16.0 1.26.4-160000.1.1
- go1.26 openSUSE Tumbleweed 1.26.3-1.1
- go1.25 openSUSE Tumbleweed 1.25.10-1.1
opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:21319-1openSUSE-SU-2026:21254-1openSUSE-SU-2026:10741-1openSUSE-SU-2026:10723-1
- delve AlmaLinux 8 1.25.2-1.module_el8.10.0+4074+24330916
- golang AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- go-toolset AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- golang-bin AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- golang-src AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- golang-misc AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- golang-race AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
- golang-tests AlmaLinux 8 1.25.10-1.module_el8.10.0+4187+c45165c4
almalinux advisories ALSA-2026:22112ALSA-2026:22121
- golang Rocky Linux 10 1.26.3-4.el10_2
- golang Rocky Linux 9 1.26.3-1.el9_8
- delve Rocky Linux 8 1.25.2-1.module+el8.10.0+40035+ee0a7047
- golang Rocky Linux 8 1.25.10-1.module+el8.10.0+40200+0fd0f175
rocky linux advisories RLSA-2026:22120RLSA-2026:22121RLSA-2026:22112
- go Alpine 3.23 1.25.10-r0
- go Alpine 3.24 1.26.3-r0
- rclone Alpine 3.24 1.74.1-r0
alpine advisories ALPINE-CVE-2026-39836
Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0
- go.dev/cl/775320 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-2026-39836 updated cvss 7.5
net: golang: Go net package: Denial of Service via NUL byte in Dial and LookupPort on Windows
-
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 Confidential Compute Attestation build-of-trustee/trustee-rhel9-operator, openshift-sandboxed-containers/osc-monitor-rhel9, confidential-compute-attestation-tech-preview/trustee-rhel9-operator Red Hat Cryostat 4 cryostat/cryostat-storage-rhel9 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-operatoraffected: workaround, no fix available
+7 more productsfewer
Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9 Red Hat Migration Toolkit for Applications 8 mta/mta-cli-rhel9 Red Hat mirror registry for Red Hat OpenShift openshift/mirror-registry-rhel8 Red Hat Multicluster Engine for Kubernetes multicluster-engine/work-rhel9, multicluster-engine/maestro-rhel9, multicluster-engine/placement-rhel9, multicluster-engine/addon-manager-rhel9, multicluster-engine/multicloud-manager-rhel9, multicluster-engine/registration-operator-rhel9, +2 more Red Hat Multicluster Global Hub multicluster-globalhub/multicluster-globalhub-agent-rhel8 Red Hat Network Observability Operator network-observability/network-observability-cli-rhel9 Red Hat OpenShift API for Data Protection oadp/oadp-velero-rhel9 -
Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-rhel9-operatoraffected: workaround, no fix planned “Will not fix”
-
Red Hat OpenShift Pipelines openshift-pipelines-client Red Hat OpenShift Service Mesh 2 openshift-service-mesh/kiali-rhel8, openshift4/ose-docker-builder-rhel9 Red Hat Power monitoring for Red Hat OpenShift openshift-power-monitoring/kepler-rhel9affected: workaround, no fix available
-
Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel9-operatoraffected: workaround, no fix planned “Will not fix”
-
Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/klusterlet-addon-controller-rhel9 Red Hat AMQ Clients python39-qpid-proton Red Hat Ansible Automation Platform 2 receptor, ansible-automation-platform/platform-operator-bundle Red Hat build of Apicurio Registry 2 apicurio/apicurio-registry-rhel8-operator, apicurio/apicurio-registry-rhel9-operator Red Hat Ceph Storage 5 rhceph/snmp-notifier-rhel8 Red Hat Ceph Storage 6 rhceph/snmp-notifier-rhel9affected: workaround, no fix available
+2 more productsfewer
Red Hat Ceph Storage 9 rhceph/alloy-rhel10 Red Hat Certification Program for Red Hat Enterprise Linux 9 redhat-certification-preflight -
Red Hat Edge Manager 1 flightctl, rhem/flightctl-ui-rhel9affected: workaround, no fix planned “Will not fix”
-
Red Hat Enterprise Linux 7 rhc-worker-script Red Hat Enterprise Linux 9 rhel9/bootc-image-builder, rhel9-eus/rhel-9.6-bootc-image-builder Red Hat Enterprise Linux 10 rhel10/bootc-image-builder, rhel10-eus/rhel-10.0-bootc-image-builder Red Hat Enterprise Linux AI (RHEL AI) 3 golang Red Hat Lightspeed for Runtimes Operator rh-lightspeed-runtimes/runtimes-inventory-rhel9-operator Red Hat OpenShift AI (RHOAI) rhoai/odh-rhel9-operatoraffected: workaround, no fix available
+6 more productsfewer
Red Hat OpenShift Dev Spaces devspaces/udi-rhel9 Red Hat OpenShift Dev Workspaces Operator devworkspace/devworkspace-rhel9-operator Red Hat OpenShift distributed tracing 3 rhosdt/tempo-rhel9 Red Hat OpenShift GitOps openshift-gitops-1/dex-rhel8 Red Hat Service Interconnect 1 qpid-proton, skupper-cli Red Hat Trusted Artifact Signer rhtas/ec-rhel9 -
Red Hat multicluster engine for Kubernetes 2.11 multicluster-engine/backplane-rhel9-operator 1786911952, multicluster-engine/hypershift-addon-rhel9-operator 1786912006fixed: vendor fix RHSA-2026:57194
15 more fixed, 57 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
- 6 mo ago
Exploit prediction
0.63% chance of exploitation in the next 30 days, higher than 50% 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 |
| NVD | 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 | <1.25.10 >=1.26.0-0, <1.26.3 |
1.25.10 1.26.3 |
| go | stdlib | <1.25.10 >=1.26.0-0, <1.26.3 |
1.25.10 1.26.3 |
Affected products
- Go standard library net
Classification
- Weakness
-
- CWE-476 NULL Pointer Dereference
References
-
go.dev
/cl/775320
patch
-
pkg.go.dev
/vuln/GO-2026-4971
vendor-advisory, advisory
-
go.dev
/issue/79006
issue-tracking, report
-
groups.google.com
/g/golang-announce/c/qcCIEXso47M
issue-tracking, mailing-list, report, web
-
nvd.nist.gov
/vuln/detail/CVE-2026-39836
web
Sources
- CVE List CVE-2026-39836
- NVD CVE-2026-39836
- OSV BIT-golang-2026-39836
- OSV GO-2026-4971
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.