{"id":"CVE-2026-90393","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acq…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acq…","severity":"high","vendor":"Linux","product":"Linux","affected":["Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < d462b5481d77ce7df8a5ff89a699386f00c9214d","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < bdddf3e1493ee973619c154a57071ce67f78598b","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 79a66fd997d4eecf17302d613194879eb32e0986","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < f4ce6803df4095777191d800bebc50219b615ca0","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 277168cb9d153ce8e9c3f9275670e32ae61b41d6","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < bda86e9f31b9a296b6e64a51c91dc776fc9f613e","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 923f559e95b89b33c7e1793b3d8f7f4ec9b2e4b7","Linux >= 7f045a49fee04b5662cbdeaf0838f9322ae8c63a < 5c5997836381010fc5907b36bc17d3b19407e933","Linux 5.8"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:38.903","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90393","references":[{"url":"https://git.kernel.org/stable/c/277168cb9d153ce8e9c3f9275670e32ae61b41d6","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5c5997836381010fc5907b36bc17d3b19407e933","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/79a66fd997d4eecf17302d613194879eb32e0986","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/923f559e95b89b33c7e1793b3d8f7f4ec9b2e4b7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bda86e9f31b9a296b6e64a51c91dc776fc9f613e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/bdddf3e1493ee973619c154a57071ce67f78598b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d462b5481d77ce7df8a5ff89a699386f00c9214d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f4ce6803df4095777191d800bebc50219b615ca0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90393.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-90393"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2536404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90393"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90393"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90393.mbox"},{"url":"https://kernelcve.org/list/?q=CVE-2026-90393"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-09-17T16:21:47.803Z","epss":0.00233,"epssPercentile":0.14101,"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","CWE-416"],"slug":"CVE-2026-90393","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix potential UAF in bpf_netns_link_update_prog\n\nIn bpf_netns_link_update_prog, the checks for old_prog and prog type\nare currently performed locklessly before acquiring netns_bpf_mutex.\nThis creates a race condition that can lead to a UAF issue.\n\nIf two threads concurrently execute BPF_LINK_UPDATE on the same netns\nlink, the following execution path can trigger a UAF:\n\nCPU0                                          CPU1\nbpf_netns_link_update_prog\n  if (old_prog && old_prog != link->prog)\n    return -EPERM;\n                                              bpf_netns_link_update_prog\n                                                if (old_prog && old_prog != link->prog)\n                                                ...\n                                                old_prog = xchg(&link->prog, new_prog);\n                                                bpf_prog_put(old_prog);\n  if (new_prog->type != link->prog->type) <-- trigger UAF\n\nFix this by moving the old_prog and prog->type checks inside the\nnetns_bpf_mutex critical section. Meanwhile, use guard() to simplify\nlock management and avoid all the goto jumping.\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, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-90393.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":225613,"id":"CVE-2026-90393","ts":1792498316814,"field":"cvss","old":null,"new":"7"},{"seq":225612,"id":"CVE-2026-90393","ts":1792498316814,"field":"severity","old":"none","new":"high"}]}