{"id":"CVE-2026-98487","title":"kernel: net: bridge: mdb: restart port group walk after deletion (CVE-2026-98487)","summary":"A flaw was found in the Linux kernel's network bridge subsystem. When deleting multicast database (MDB) port groups, the kernel can maintain a stale reference to memory that has already been freed during recursive group removal, resulting …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":"CWE-416","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 6","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-10-18","updated":"2026-10-24","sourceUpdated":"2026-10-24T14:27:50+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98487.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98487.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98487"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2554847"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98487"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98487"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98487.mbox"},{"url":"https://kernelcve.org/list/?q=CVE-2026-98487"},{"url":"https://git.kernel.org/stable/c/46ec55855c972504258c371677ac039ba20e5d12"},{"url":"https://git.kernel.org/stable/c/ab3c4a4c85f2e1e8d04b5c1770dea8412d21c7fe"},{"url":"https://git.kernel.org/stable/c/fe2a42789c12eb7c5d3a42191e2cc735a6c35ead"},{"url":"https://git.kernel.org/stable/c/ab1404ac81154a89fb61ac50ae9a04cd8d4834dc"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00164,"epssPercentile":0.05537,"scores":{"vendor":5.5,"cna":7.8},"ingestedAt":"2026-10-18T15:45:12.292Z","slug":"CVE-2026-98487","body":"## Overview\n\nA flaw was found in the Linux kernel's network bridge subsystem. When deleting multicast database (MDB) port groups, the kernel can maintain a stale reference to memory that has already been freed during recursive group removal, resulting in a use-after-free condition. A local attacker could exploit this vulnerability through bridge management operations to trigger a system crash, leading to a Denial of Service (DoS), or potentially achieve privilege escalation.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98487.json)\n\n**kernel: net: bridge: mdb: restart port group walk after deletion** — rated Moderate by Red Hat. Released 2026-10-18, updated 2026-10-24.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 6\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNot affected:\n\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nOut of support scope\n\nWorkarounds / mitigations:\n\n- Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":229510,"id":"CVE-2026-98487","ts":1793019826455,"field":"cvss","old":"7.8","new":"5.5"},{"seq":229509,"id":"CVE-2026-98487","ts":1793019826455,"field":"severity","old":"high","new":"medium"},{"seq":228950,"id":"CVE-2026-98487","ts":1792854118830,"field":"cvss","old":"5.5","new":"7.8"},{"seq":228949,"id":"CVE-2026-98487","ts":1792854118830,"field":"severity","old":"medium","new":"high"},{"seq":227122,"id":"CVE-2026-98487","ts":1792585140263,"field":"cvss","old":null,"new":"5.5"},{"seq":227121,"id":"CVE-2026-98487","ts":1792585140263,"field":"severity","old":"none","new":"medium"}]}