{"id":"CVE-2026-74255","title":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix UAF in tipc_l2_send_msg()\n\nSyzbot reported a slab-use-after-free in ipvlan_hard_header() when\ncalled from tipc_l2_send_msg().\n\nThe root cause is that tipc_dis…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix UAF in tipc_l2_send_msg()\n\nSyzbot reported a slab-use-after-free in ipvlan_hard_header() when\ncalled from tipc_l2_send_msg().\n\nThe root cause is that tipc_dis…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 8","enterprise_linux 9"],"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:17:34.157","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-74255","references":[{"url":"https://git.kernel.org/stable/c/0d8a12d7143126afdf9fbe2e3d438650dd6603ed","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/35e0297a93c3c34a3924eeef816c03504e3ab5c5","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/50ff092633b06382e5091dd5b093ce943d4ac2f9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/609ced2301be1df7e7ed2ef47d1d916674e6ba3b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/71aafa16d79b107b33837f60b6cbc7d0cb8c5708","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aef12b5ce793dea6b3a97a58fd0f946000ae8945","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f4002f1c669cc02e3763f479fc25ff1dfa9e2420","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f4c3d89fc986b0da196ddfc6cfe0ea5d5d08bec6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74255.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-74255"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2516778"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74255"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74255"},{"url":"https://kernelcve.org/list/?q=CVE-2026-74255"},{"url":"https://lore.kernel.org/linux-cve-announce/2026081541-CVE-2026-74255-caef@gregkh/T"}],"tags":["nvd","csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.005,"epssPercentile":0.42614,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T18:51:21.997322Z"},"scores":{"nvd":9.8,"vendor":4.7,"cna":9.8},"ingestedAt":"2026-10-16T19:46:24.389Z","slug":"CVE-2026-74255","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ntipc: fix UAF in tipc_l2_send_msg()\n\nSyzbot reported a slab-use-after-free in ipvlan_hard_header() when\ncalled from tipc_l2_send_msg().\n\nThe root cause is that tipc_disable_l2_media() calls synchronize_net()\nwhile b->media_ptr is still valid. This allows concurrent RCU readers\nto obtain the device pointer after synchronize_net() has finished.\nThe pointer is cleared later in bearer_disable(), but without any\nsubsequent synchronization, allowing the device to be freed while\nstill in use by readers.\n\nFix this by clearing b->media_ptr in tipc_disable_l2_media() before\ncalling synchronize_net().\n\nThis is safe to do now because the call order in bearer_disable()\nwas reversed in 0d051bf93c06 (\"tipc: make bearer packet filtering generic\")\nto call tipc_node_delete_links() (which needs the pointer) before\ndisable_media().\n\nhttps: //lore.kernel.org/netdev/6a2c1007.428ffe26.258b27.015d.GAE@google.com/T/#u\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, 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-2026-74255.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":230311,"id":"CVE-2026-74255","ts":1793130917318,"field":"cvss","old":"4.7","new":"9.8"},{"seq":230310,"id":"CVE-2026-74255","ts":1793130917318,"field":"severity","old":"medium","new":"critical"},{"seq":229326,"id":"CVE-2026-74255","ts":1793019687798,"field":"cvss","old":"9.8","new":"4.7"},{"seq":229325,"id":"CVE-2026-74255","ts":1793019687798,"field":"severity","old":"critical","new":"medium"}]}