--- id: CVE-2026-6733 title: >- undici: Undici: Response queue poisoning on reused keep-alive sockets can lead to incorrect response delivery. (CVE-2026-6733) summary: >- A flaw was found in undici. An attacker-controlled upstream server can exploit a vulnerability in Undici's HTTP/1.1 client, specifically related to response queue poisoning on reused keep-alive sockets. This allows the attacker to inject a… severity: low cvss: 3.7 cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N' cvssSource: vendor cwe: - CWE-940 - CWE-367 vendor: Red Hat product: Red Hat Enterprise Linux AppStream (v. 8) affected: - cryostat 4 - openshift_pipelines - amq_broker 7 - build_of_podman_desktop - developer_hub - enterprise_linux 8 - hardened_images - openshift_ai_rhoai - openshift_container_platform 4 - openshift_dev_spaces - self_service_automation_portal 2 - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_8 - enterprise_linux_appstream_v_9 - openshift_data_foundation 4.18 patched: - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_8 - enterprise_linux_appstream_v_9 - hardened_images - openshift_data_foundation 4.18 published: '2026-06-17' updated: '2026-10-01' sourceUpdated: '2026-10-01T18:24:03+00:00' source: CSAF sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6733.json' references: - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6733.json - url: 'https://access.redhat.com/security/cve/CVE-2026-6733' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2490006' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-6733' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-6733' - url: 'https://cna.openjsf.org/security-advisories.html' - url: 'https://github.com/nodejs/undici/security/advisories/GHSA-35p6-xmwp-9g52' - url: 'https://hackerone.com/reports/3582376' - url: 'https://access.redhat.com/errata/RHSA-2026:35842' - url: 'https://access.redhat.com/errata/RHSA-2026:35841' - url: 'https://access.redhat.com/errata/RHSA-2026:41947' - url: 'https://access.redhat.com/errata/RHSA-2026:39868' - url: 'https://access.redhat.com/errata/RHSA-2026:35892' - url: 'https://access.redhat.com/errata/RHSA-2026:35891' - url: 'https://access.redhat.com/errata/RHSA-2026:38236' - url: 'https://access.redhat.com/errata/RHSA-2026:38009' - url: 'https://access.redhat.com/errata/RHSA-2026:56431' - url: 'https://github.com/advisories/GHSA-35p6-xmwp-9g52' tags: - csaf - vex - red-hat - ghsa - npm epss: 0.0022 epssPercentile: 0.12416 ecosystem: npm ingestedAt: '2026-06-22T15:59:08.198Z' --- ## Overview A flaw was found in undici. An attacker-controlled upstream server can exploit a vulnerability in Undici's HTTP/1.1 client, specifically related to response queue poisoning on reused keep-alive sockets. This allows the attacker to inject an unsolicited HTTP/1.1 response onto an idle socket. Consequently, when the client dispatches a new request on that socket, it may associate the injected response with the new request, leading to responses being delivered to unintended recipients or requests. This could result in a low impact on data integrity. ## Vendor advisories - **RHSA-2026:35842** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-07-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:35842) - **RHSA-2026:35841** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10) · released 2026-07-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:35841) - **RHSA-2026:41947** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-07-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:41947) - **RHSA-2026:39868** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 8) · released 2026-07-15 · [advisory](https://access.redhat.com/errata/RHSA-2026:39868) - **RHSA-2026:35892** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-07-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:35892) - **RHSA-2026:35891** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9) · released 2026-07-06 · [advisory](https://access.redhat.com/errata/RHSA-2026:35891) - **RHSA-2026:38236** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:38236) - **RHSA-2026:38009** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-07-10 · [advisory](https://access.redhat.com/errata/RHSA-2026:38009) - **RHSA-2026:56431** · Red Hat · fixed in: Red Hat Openshift Data Foundation 4.18 · released 2026-08-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:56431) - **Red Hat VEX** · Low · affected: Cryostat 4, OpenShift Pipelines, Red Hat AMQ Broker 7, Red Hat Build of Podman Desktop, Red Hat Developer Hub, Red Hat Enterprise Linux 8, … · no fix planned: Cryostat 4, OpenShift Pipelines, Red Hat AMQ Broker 7, Red Hat Build of Podman Desktop, … · updated 2026-10-01 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6733.json) **undici: Undici: Response queue poisoning on reused keep-alive sockets can lead to incorrect response delivery.** — rated Low by Red Hat. Released 2026-06-17, updated 2026-10-01. Affected: - Cryostat 4 - OpenShift Pipelines - Red Hat AMQ Broker 7 - Red Hat Build of Podman Desktop - Red Hat Developer Hub - Red Hat Enterprise Linux 8 - Red Hat Hardened Images - Red Hat OpenShift AI (RHOAI) - Red Hat OpenShift Container Platform 4 - Red Hat OpenShift Dev Spaces - Self-service automation portal 2 Fixed: - Red Hat Enterprise Linux AppStream (v. 10) - Red Hat Enterprise Linux AppStream (v. 8) - Red Hat Enterprise Linux AppStream (v. 9) - Red Hat Hardened Images - Red Hat Openshift Data Foundation 4.18 No fix planned: - Cryostat 4 - OpenShift Pipelines - Red Hat AMQ Broker 7 - Red Hat Build of Podman Desktop - Red Hat Developer Hub - Red Hat Enterprise Linux 8 - Red Hat Hardened Images - Red Hat OpenShift AI (RHOAI) - Red Hat OpenShift Container Platform 4 - Red Hat OpenShift Dev Spaces - Self-service automation portal 2 Not affected: - Red Hat Openshift Data Foundation 4.18 - Red Hat Hardened Images ## Remediation For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:35842 For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:35841 For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 https://access.redhat.com/errata/RHSA-2026:41947 Workarounds / mitigations: - Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. ## Package advisory (CVE-2026-6733) Affected packages: - `undici < 6.27.0` - `undici >= 7.0.0, < 7.28.0` - `undici >= 8.0.0, < 8.5.0` Patched in: - `undici 6.27.0` - `undici 7.28.0` - `undici 8.5.0` Source: https://github.com/advisories/GHSA-35p6-xmwp-9g52