{"id":"CVE-2026-68338","title":"kernel: net/packet: avoid fanout hook re-registration after unregister (CVE-2026-68338)","summary":"A flaw was found in the Linux kernel's `net/packet` subsystem. A race condition can occur during the re-registration of a fanout hook after a network device has been unregistered. This issue arises when the `packet_set_ring()` function att…","severity":"high","cvss":7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-367","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 7","enterprise_linux 8","enterprise_linux 9","enterprise_linux_baseos_v_8","enterprise_linux_crb_v_8"],"patched":["enterprise_linux_baseos_v_8","enterprise_linux_crb_v_8"],"published":"2026-08-10","updated":"2026-10-26","sourceUpdated":"2026-10-26T09:32:28+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-68338"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2513264"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-68338"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68338"},{"url":"https://lore.kernel.org/linux-cve-announce/2026081036-CVE-2026-68338-8547@gregkh/T"},{"url":"https://access.redhat.com/errata/RHSA-2026:89083"},{"url":"https://git.kernel.org/stable/c/acb40ebfa5c4d62f84339fcbf713f2a9fd033a71"},{"url":"https://git.kernel.org/stable/c/c820f4b7f2fa38f8769db0d0cefdd94e2721504d"},{"url":"https://git.kernel.org/stable/c/4628efbdc7affd094181f5263e65c1062e31f15f"},{"url":"https://git.kernel.org/stable/c/80ec024d53a05c60ad1d08968dcf745f10c1665c"},{"url":"https://git.kernel.org/stable/c/0a052e0808e015e68144a9877e6ef42b952c49fa"},{"url":"https://git.kernel.org/stable/c/1bc55c29cd85818e9052f17deb287d5a11fb817f"},{"url":"https://git.kernel.org/stable/c/a885387dae7986a55bae5c77a15bdd447f64e9b9"},{"url":"https://git.kernel.org/stable/c/50aff80475abd3533eef4320477037e6fcc6b56e"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00136,"epssPercentile":0.03046,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:47:16.591778Z"},"scores":{"vendor":7,"cna":7.8},"ingestedAt":"2026-10-16T17:24:46.858Z","slug":"CVE-2026-68338","body":"## Overview\n\nA flaw was found in the Linux kernel's `net/packet` subsystem. A race condition can occur during the re-registration of a fanout hook after a network device has been unregistered. This issue arises when the `packet_set_ring()` function attempts to re-add a fanout hook based on a stale state, potentially leading to an inconsistent system state and a denial of service (DoS).\n\n## Vendor advisories\n\n- **RHSA-2026:89083** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:89083)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json)\n\n**kernel: net/packet: avoid fanout hook re-registration after unregister** — rated Moderate by Red Hat. Released 2026-08-10, updated 2026-10-26.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n\nFixed:\n\n- Red Hat Enterprise Linux BaseOS (v. 8)\n- Red Hat Enterprise Linux CRB (v. 8)\n\nNo fix planned:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat Enterprise Linux 9\n\nNot affected:\n\n- Red Hat Enterprise Linux 6\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\n\nThe system must be rebooted for this update to take effect.\n\nRed Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.\n\nBecause of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:89083","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":229358,"id":"CVE-2026-68338","ts":1793019712406,"field":"cvss","old":"7.8","new":"7"}]}