{"id":"CVE-2026-39825","title":"net/http/httputil: golang: net/http/httputil: ReverseProxy forwards hidden query parameters, potentially bypassing security controls (CVE-2…","summary":"A flaw was found in the `net/http/httputil` package, specifically within the `ReverseProxy` component. This vulnerability allows the `ReverseProxy` to forward query parameters that are not visible to `Rewrite` functions. This occurs becaus…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","cvssSource":"vendor","cwe":"CWE-472","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4.22","affected":["assisted_installer_for_red_hat_openshift_container_platform 2","builds_for_red_hat_openshift","cert_manager_operator_for_red_hat_openshift","compliance_operator","confidential_compute_attestation","cryostat 4","custom_metric_autoscaler_operator_for_red_hat_openshift","deployment_validation_operator","external_secrets_operator_for_red_hat_openshift","fence_agents_remediation_operator","file_integrity_operator","logging_subsystem_for_red_hat_openshift","logical_volume_manager_storage","migration_toolkit_for_applications 8","migration_toolkit_for_containers","multiarch_tuning_operator","multicluster_engine_for_kubernetes","multicluster_global_hub","network_observability_operator","node_healthcheck_operator","openshift_developer_tools_and_services","openshift_lightspeed","openshift_pipelines","openshift_serverless","openshift_service_mesh 3","power_monitoring_for_red_hat_openshift","3scale_api_management_platform 2","advanced_cluster_management_for_kubernetes 2","advanced_cluster_security 4","ansible_automation_platform 2","ceph_storage 5","ceph_storage 6","ceph_storage 9","certification_program_for_red_hat_enterprise_linux 9","connectivity_link 1","developer_hub","edge_manager 1","enterprise_linux 10","enterprise_linux 7","enterprise_linux 8"],"patched":["enterprise_linux_appstream_eus_v_10_0","enterprise_linux_appstream_v_10","enterprise_linux_appstream_v_8","enterprise_linux_appstream_e4s_v_9_2","enterprise_linux_appstream_e4s_v_9_4","enterprise_linux_appstream_eus_v_9_6","enterprise_linux_appstream_v_9","openshift_api_for_data_protection 1.6","hardened_images","openshift_container_platform 4.22","openshift_service_mesh 3.0","openshift_service_mesh 3.1","openshift_service_mesh 3.2","openshift_service_mesh 3.3","openshift_service_mesh 3.4","multicluster_engine_for_kubernetes 2.11"],"published":"2026-05-07","updated":"2026-09-23","sourceUpdated":"2026-09-23T03:44:17+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39825.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39825.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-39825"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2467823"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-39825"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-39825"},{"url":"https://go.dev/cl/770541"},{"url":"https://go.dev/issue/78948"},{"url":"https://groups.google.com/g/golang-announce/c/qcCIEXso47M"},{"url":"https://pkg.go.dev/vuln/GO-2026-4976"},{"url":"https://access.redhat.com/errata/RHSA-2026:49702"},{"url":"https://access.redhat.com/errata/RHSA-2026:22120"},{"url":"https://access.redhat.com/errata/RHSA-2026:22112"},{"url":"https://access.redhat.com/errata/RHSA-2026:61253"},{"url":"https://access.redhat.com/errata/RHSA-2026:57649"},{"url":"https://access.redhat.com/errata/RHSA-2026:49712"},{"url":"https://access.redhat.com/errata/RHSA-2026:22121"},{"url":"https://access.redhat.com/errata/RHSA-2026:43692"},{"url":"https://access.redhat.com/errata/RHSA-2026:23262"},{"url":"https://access.redhat.com/errata/RHSA-2026:23264"},{"url":"https://access.redhat.com/errata/RHSA-2026:63096"},{"url":"https://access.redhat.com/errata/RHSA-2026:65106"},{"url":"https://access.redhat.com/errata/RHSA-2026:65112"},{"url":"https://access.redhat.com/errata/RHSA-2026:65113"},{"url":"https://access.redhat.com/errata/RHSA-2026:65115"},{"url":"https://access.redhat.com/errata/RHSA-2026:65121"},{"url":"https://access.redhat.com/errata/RHSA-2026:57194"},{"url":"https://access.redhat.com/errata/RHSA-2026:59556"}],"tags":["csaf","vex","red-hat","osv","go"],"epss":0.0039,"epssPercentile":0.33023,"aliases":["GO-2026-4976","BIT-golang-2026-39825"],"ecosystem":"go","ingestedAt":"2026-08-26T19:27:02.291Z","slug":"CVE-2026-39825","body":"## Overview\n\nA flaw was found in the `net/http/httputil` package, specifically within the `ReverseProxy` component. This vulnerability allows the `ReverseProxy` to forward query parameters that are not visible to `Rewrite` functions. This occurs because the `ReverseProxy` does not correctly consider the `url.ParseQuery` limit on the total number of query parameters. A remote attacker could exploit this to send hidden query parameters, potentially bypassing security policies or controls implemented by `Rewrite` functions, leading to information disclosure or unexpected behavior.\n\n## Vendor advisories\n\n- **RHSA-2026:49702** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · released 2026-08-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:49702)\n- **RHSA-2026:22120** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-06-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:22120)\n- **RHSA-2026:22112** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-06-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:22112)\n- **RHSA-2026:61253** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.2) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61253)\n- **RHSA-2026:57649** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream E4S (v.9.4) · released 2026-08-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:57649)\n- **RHSA-2026:49712** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.6) · released 2026-08-03 · [advisory](https://access.redhat.com/errata/RHSA-2026:49712)\n- **RHSA-2026:22121** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-06-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:22121)\n- **RHSA-2026:43692** · Red Hat · fixed in: OpenShift API for Data Protection 1.6 · released 2026-07-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:43692)\n- **RHSA-2026:23262** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:23262)\n- **RHSA-2026:23264** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-06-04 · [advisory](https://access.redhat.com/errata/RHSA-2026:23264)\n- **RHSA-2026:63096** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.22 · released 2026-09-08 · [advisory](https://access.redhat.com/errata/RHSA-2026:63096)\n- **Red Hat VEX** · Moderate · affected: Assisted Installer for Red Hat OpenShift Container Platform 2, Builds for Red Hat OpenShift, cert-manager Operator for Red Hat OpenShift, Compliance Operator, Confidential Compute Attestation, Cryostat 4, … · no fix planned: Assisted Installer for Red Hat OpenShift Container Platform 2, Builds for Red Hat OpenShift, cert-manager Operator for Red Hat OpenShift, Compliance Operator, … · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39825.json)\n- **RHSA-2026:57194** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:57194)\n\n**net/http/httputil: golang: net/http/httputil: ReverseProxy forwards hidden query parameters, potentially bypassing security controls** — rated Moderate by Red Hat. Released 2026-05-07, updated 2026-09-23.\n\nAffected:\n\n- Assisted Installer for Red Hat OpenShift Container Platform 2\n- Builds for Red Hat OpenShift\n- cert-manager Operator for Red Hat OpenShift\n- Compliance Operator\n- Confidential Compute Attestation\n- Cryostat 4\n- Custom Metric Autoscaler operator for Red Hat Openshift\n- Deployment Validation Operator\n- External Secrets Operator for Red Hat OpenShift\n- Fence Agents Remediation Operator\n- File Integrity Operator\n- Logging Subsystem for Red Hat OpenShift\n- Logical Volume Manager Storage\n- Migration Toolkit for Applications 8\n- Migration Toolkit for Containers\n- Multiarch Tuning Operator\n- Multicluster Engine for Kubernetes\n- Multicluster Global Hub\n- Network Observability Operator\n- Node HealthCheck Operator\n- OpenShift Developer Tools and Services\n- OpenShift Lightspeed\n- OpenShift Pipelines\n- OpenShift Serverless\n- OpenShift Service Mesh 3\n- Power monitoring for Red Hat OpenShift\n- Red Hat 3scale API Management Platform 2\n- Red Hat Advanced Cluster Management for Kubernetes 2\n- Red Hat Advanced Cluster Security 4\n- Red Hat Ansible Automation Platform 2\n- Red Hat Ceph Storage 5\n- Red Hat Ceph Storage 6\n- Red Hat Ceph Storage 9\n- Red Hat Certification Program for Red Hat Enterprise Linux 9\n- Red Hat Connectivity Link 1\n- Red Hat Developer Hub\n- Red Hat Edge Manager 1\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n\nFixed:\n\n- Red Hat Enterprise Linux AppStream EUS (v. 10.0)\n- Red Hat Enterprise Linux AppStream (v. 10)\n- Red Hat Enterprise Linux AppStream (v. 8)\n- Red Hat Enterprise Linux AppStream E4S (v.9.2)\n- Red Hat Enterprise Linux AppStream E4S (v.9.4)\n- Red Hat Enterprise Linux AppStream EUS (v.9.6)\n- Red Hat Enterprise Linux AppStream (v. 9)\n- OpenShift API for Data Protection 1.6\n- Red Hat Hardened Images\n- Red Hat OpenShift Container Platform 4.22\n- Red Hat OpenShift Service Mesh 3.0\n- Red Hat OpenShift Service Mesh 3.1\n- Red Hat OpenShift Service Mesh 3.2\n- Red Hat OpenShift Service Mesh 3.3\n- Red Hat OpenShift Service Mesh 3.4\n- multicluster engine for Kubernetes 2.11\n\nNo fix planned:\n\n- Assisted Installer for Red Hat OpenShift Container Platform 2\n- Builds for Red Hat OpenShift\n- cert-manager Operator for Red Hat OpenShift\n- Compliance Operator\n- Confidential Compute Attestation\n- Cryostat 4\n- Custom Metric Autoscaler operator for Red Hat Openshift\n- Deployment Validation Operator\n- External Secrets Operator for Red Hat OpenShift\n- Fence Agents Remediation Operator\n- File Integrity Operator\n- Logging Subsystem for Red Hat OpenShift\n- Logical Volume Manager Storage\n- Migration Toolkit for Applications 8\n- Migration Toolkit for Containers\n- Multiarch Tuning Operator\n- Multicluster Engine for Kubernetes\n- Multicluster Global Hub\n- Network Observability Operator\n- Node HealthCheck Operator\n- OpenShift Developer Tools and Services\n- OpenShift Lightspeed\n- OpenShift Pipelines\n- OpenShift Serverless\n- OpenShift Service Mesh 3\n- Power monitoring for Red Hat OpenShift\n- Red Hat 3scale API Management Platform 2\n- Red Hat Advanced Cluster Management for Kubernetes 2\n- Red Hat Advanced Cluster Security 4\n- Red Hat Ansible Automation Platform 2\n- Red Hat Ceph Storage 5\n- Red Hat Ceph Storage 6\n- Red Hat Ceph Storage 9\n- Red Hat Certification Program for Red Hat Enterprise Linux 9\n- Red Hat Connectivity Link 1\n- Red Hat Developer Hub\n- Red Hat Edge Manager 1\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n\nNot affected:\n\n- OpenShift API for Data Protection 1.6\n- Red Hat OpenShift Container Platform 4.22\n- Red Hat OpenShift Service Mesh 3.0\n- Red Hat OpenShift Service Mesh 3.1\n- Red Hat OpenShift Service Mesh 3.2\n- Red Hat OpenShift Service Mesh 3.3\n- Red Hat OpenShift Service Mesh 3.4\n- multicluster engine for Kubernetes 2.11\n\n## Remediation\n\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:49702\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:22120\nFor details on how to apply this update, which includes the changes described in this advisory, refer to:\n\nhttps://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:22112\n\nWorkarounds / mitigations:\n\n- Increase the maximum number of query parameters allowed by setting the GODEBUG environment variable `urlmaxqueryparams` to a higher value (e.g., `GODEBUG=urlmaxqueryparams=20000`), or validate and enforce security controls on query parameters at the backend service rather than relying solely on the ReverseProxy's Rewrite or Director function for security filtering.\n\n## Package advisory (CVE-2026-39825)\n\nAffected packages:\n\n- `stdlib >= 1.26.0-0, < 1.26.3`\n\nPatched in:\n\n- `stdlib 1.26.3`\n\nSource: https://osv.dev/vulnerability/GO-2026-4976","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":5154,"id":"CVE-2026-39825","ts":1788887250919,"field":"cvss","old":null,"new":"6.5"},{"seq":5153,"id":"CVE-2026-39825","ts":1788887250919,"field":"severity","old":"none","new":"medium"},{"seq":4037,"id":"CVE-2026-39825","ts":1788886366829,"field":"cvss","old":"6.5","new":null},{"seq":4036,"id":"CVE-2026-39825","ts":1788886366829,"field":"severity","old":"medium","new":"none"},{"seq":3167,"id":"CVE-2026-39825","ts":1788883133178,"field":"cvss","old":null,"new":"6.5"},{"seq":3166,"id":"CVE-2026-39825","ts":1788883133178,"field":"severity","old":"none","new":"medium"}]}