CVE-2026-42504 json
Quadratic complexity in WordDecoder.DecodeHeader in mime
published 2026-06-02 5 mo ago modified 2026-11-09 4 h ago also BIT-golang-2026-42504 , EUVD-2026-34039 , GO-2026-5038
- 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 46%
- public exploits
- 0
- none known
Summary
Decoding a maliciously-crafted MIME header containing many invalid encoded-words can consume excessive CPU.
Patch / fix
- bitnami golang 1.25.11, 1.26.4
- go stdlib 1.25.11, 1.26.4
- Go standard library mime 1.25.11, 1.26.4
- golang-1.26 Debian 14 1.26.4-1
debian advisories DEBIAN-CVE-2026-42504
- microshift openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-olm openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-multus openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-selinux openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-greenboot openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-networking openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-release-info openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
- microshift-olm-release-info openshift 4.16 4.16.73-202610151747.p0.g44abd51.assembly.4.16.73.el9
red hat advisories RHSA-2026:83631RHSA-2026:80167RHSA-2026:77319RHSA-2026:74797RHSA-2026:76795RHSA-2026:76809
- 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
- go1.25-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
- go1.25 SLES for SAP applications 16.0, SLES 16.0 1.25.11-160000.1.1
- go1.26 SLES for SAP applications 16.0, SLES 16.0 1.26.4-160000.1.1
suse advisories SUSE-SU-2026:3151-1SUSE-SU-2026:3102-1SUSE-SU-2026:3047-1SUSE-SU-2026:3046-1SUSE-SU-2026:22638-1SUSE-SU-2026:22572-1
- kured openSUSE Tumbleweed 1.23.0-1.1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
- rclone openSUSE Leap 16.0 1.74.4-bp160.1.1
- 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
- inspektor-gadget openSUSE Tumbleweed 0.53.2-1.1
- go1.25 openSUSE Leap 16.0 1.25.11-160000.1.1
- go1.26 openSUSE Leap 16.0 1.26.4-160000.1.1
opensuse advisories openSUSE-SU-2026:12271-1openSUSE-SU-2026:21483-1openSUSE-SU-2026:21436-1openSUSE-SU-2026:21319-1openSUSE-SU-2026:21254-1openSUSE-SU-2026:11056-1
- yggdrasil AlmaLinux 10 0.4.9.2-1.el10_2.3
- osbuild-composer AlmaLinux 8 101.5-3.el8_10.alma.1
- osbuild-composer-core AlmaLinux 8 101.5-3.el8_10.alma.1
- osbuild-composer-worker AlmaLinux 8 101.5-3.el8_10.alma.1
- opentelemetry-collector AlmaLinux 10 0.152.1-2.el10_2
- opentelemetry-collector AlmaLinux 9 0.152.1-2.el9_8
- osbuild-composer AlmaLinux 9 165.1-4.el9_8.1.alma.1
- osbuild-composer-core AlmaLinux 9 165.1-4.el9_8.1.alma.1
almalinux advisories ALSA-2026:69308ALSA-2026:67148ALSA-2026:65116ALSA-2026:65117ALSA-2026:65153ALSA-2026:63022
- yggdrasil Rocky Linux 10 0.4.9.2-1.el10_2.3
- osbuild-composer Rocky Linux 8 101.5-3.el8_10.rocky.0.6
- osbuild-composer Rocky Linux 10 165.1-3.el10_2.2.rocky.0.1
- image-builder Rocky Linux 9 52.1-1.el9_8.2
- image-builder Rocky Linux 10 52.1-1.el10_2.2.rocky.0.1
- opentelemetry-collector Rocky Linux 10 0.152.1-2.el10_2
- opentelemetry-collector Rocky Linux 9 0.152.1-2.el9_8
- osbuild-composer Rocky Linux 9 165.1-4.el9_8.1.rocky.0.1
rocky linux advisories RLSA-2026:69308RLSA-2026:67148RLSA-2026:65895RLSA-2026:65886RLSA-2026:65534RLSA-2026:65116
- go Alpine 3.24 1.26.8-r0
alpine advisories ALPINE-CVE-2026-42504
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 1.25.11-1
- golang Azure Linux 3.0 1.26.4-1
azure linux advisories AZL-89360AZL-89366
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/774481 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-2026-42504 updated cvss 7.5
mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header
-
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-rhel9affected: workaround, no fix available
-
Red Hat Confidential Compute Attestation build-of-trustee/trustee-rhel9-operator, openshift-sandboxed-containers/osc-monitor-rhel9affected: workaround, no fix planned “Will not fix”
-
Red Hat Deployment Validation Operator dvo/deployment-validation-rhel8-operatoraffected: workaround, no fix available
-
Red Hat External Secrets Operator for Red Hat OpenShift external-secrets-operator/external-secrets-rhel9affected: workaround, no fix planned “Will not fix”
-
Red Hat File Integrity Operator compliance/openshift-file-integrity-rhel8-operatoraffected: workaround, no fix available
-
Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/cluster-logging-rhel9-operatoraffected: workaround, no fix planned “Will not fix”
-
Red Hat Logical Volume Manager Storage lvms4/topolvm-rhel8 Red Hat Multiarch Tuning Operator multiarch-tuning/multiarch-tuning-rhel9-operator Red Hat Multicluster Engine for Kubernetes multicluster-engine/maestro-rhel9, multicluster-engine/assisted-service-9-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 OpenShift API for Data Protection rhacm2/config-policy-controller-rhel9, multicluster-engine/multicloud-manager-rhel9, multicluster-engine/hypershift-addon-rhel9-operatoraffected: workaround, no fix available
+4 more productsfewer
Red Hat OpenShift Developer Tools and Services helm Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-rhel9-operator Red Hat OpenShift Pipelines openshift-pipelines/pipelines-scheduler-rhel9 Red Hat OpenShift Serverless kn-workflow-plugin, openshift-serverless-clients, openshift-serverless-1/logic-rhel9-operator, openshift-serverless-1/kn-plugin-event-sender-rhel9 -
Red Hat OpenShift Service Mesh 2 openshift-service-mesh/kiali-rhel8affected: workaround, no fix planned “Will not fix”
show 5 moreshow fewer
-
Red Hat Power monitoring for Red Hat OpenShift openshift-power-monitoring/kepler-rhel9 Red Hat 3scale API Management Platform 2 3scale-amp2/3scale-rhel9-operator Red Hat Advanced Cluster Management for Kubernetes 2 redhat-user-workloads/crt-redhat-acm-tenant/thanos-acm-213, redhat-user-workloads/crt-redhat-acm-tenant/memcached-exporter-acm-211 Red Hat Certification Program for Red Hat Enterprise Linux 9 redhat-certification-preflight Red Hat Connectivity Link 1 rhcl-1/rhcl-operator-bundle Red Hat Edge Manager 1 rhem/flightctl-ui-rhel9affected: workaround, no fix available
+3 more productsfewer
Red Hat Enterprise Linux 7 rhc Red Hat Enterprise Linux 8 rhc, git-lfs Red Hat Enterprise Linux 9 rhc, ignition, grafana-pcp, ignition-edge, ignition-grub, gvisor-tap-vsock, +2 more -
Red Hat Enterprise Linux 10 butane, gvisor-tap-vsock, rhel10/bootc-image-builder, rhel10-eus/rhel-10.0-bootc-image-builderaffected: workaround, no fix available, no fix planned “Will not fix”
-
Red Hat Enterprise Linux AI (RHEL AI) 3 golang Red Hat OpenShift AI (RHOAI) rhoai/rhai-cli-rhel9 Red Hat OpenShift Cluster Manager CLI ocm-cli-clients/ocm-cli-rhel9 Red Hat OpenShift Container Platform 4 openshift4/ose-cli, openshift4/ose-ansible-operator, rh-osbs/openshift-golang-builder, openshift4/ose-vertical-pod-autoscaler-rhel9, openshift4/ose-vertical-pod-autoscaler-rhel9-operatoraffected: workaround, no fix available
-
Red Hat OpenShift Container Platform 5 openshift, openshift5/frr-rhel9, ose-crio-credential-provider, openshift5/ose-kube-rbac-proxy-rhel9, ose-aws-ecr-image-credential-provideraffected: workaround, no fix available, no fix planned “Will not fix”
-
Red Hat OpenShift Dev Workspaces Operator devworkspace/devworkspace-rhel9-operator Red Hat OpenShift distributed tracing 3 rhosdt/tempo-rhel9 Red Hat OpenShift for Windows Containers openshift4-wincw/windows-machine-config-rhel9-operator Red Hat OpenShift on AWS rosa Red Hat OpenShift Virtualization 4 kubevirt Red Hat OpenStack Platform 17.1 rhosp-rhel9/osp-director-agentaffected: workaround, no fix available
+1 more productsfewer
Red Hat Satellite 6 yggdrasil-worker-forwarder
4 more affected, 92 more fixed, 92 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
- 5 mo ago
Exploit prediction
0.56% chance of exploitation in the next 30 days, higher than 46% 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 | <1.25.11 >=1.26.0-0, <1.26.4 |
1.25.11 1.26.4 |
| go | stdlib | <1.25.11 >=1.26.0-0, <1.26.4 |
1.25.11 1.26.4 |
Affected products
- Go standard library mime
Classification
- Weakness
-
- CWE-407 Inefficient Algorithmic Complexity
References
-
go.dev
/cl/774481
web, patch
-
go.dev
/issue/79217
web, report
-
groups.google.com
/g/golang-announce/c/tKs3rmcBcKw
web
-
pkg.go.dev
/vuln/GO-2026-5038
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-42504
web
Sources
- CVE List CVE-2026-42504
- NVD CVE-2026-42504
- OSV BIT-golang-2026-42504
- OSV GO-2026-5038
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.