{"id":"CVE-2026-89738","title":"kernel: usb: gadget: at91_udc: drain polled-VBUS timer/work before udc is freed (CVE-2026-89738)","summary":"A flaw was found in the Linux kernel's `at91_udc` USB gadget driver. In polled-VBUS mode, a timing issue during driver unbinding or probe failure can lead to a use-after-free vulnerability. A local attacker could exploit this by triggering…","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-825","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","affected":["openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T17:28:12+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89738.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89738.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89738"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532232"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89738"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89738"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89738.mbox"},{"url":"https://git.kernel.org/stable/c/51a311eb97e91ce1aed3005cb71ccb2e30f8cce8"},{"url":"https://git.kernel.org/stable/c/557ef547d49ff5e6026a4d39bdd3113bd81d7688"},{"url":"https://git.kernel.org/stable/c/a2a602cb1e28d76a5398cec3fa21b0110385f501"},{"url":"https://git.kernel.org/stable/c/c27d13ce4bab80fbdf6523928071b6c24b37606c"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00164,"epssPercentile":0.06014,"scores":{"vendor":4.1,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.472Z","slug":"CVE-2026-89738","body":"## Overview\n\nA flaw was found in the Linux kernel's `at91_udc` USB gadget driver. In polled-VBUS mode, a timing issue during driver unbinding or probe failure can lead to a use-after-free vulnerability. A local attacker could exploit this by triggering a normal driver unbind operation, which may interleave with an already queued work item. This could result in system instability or a denial of service (DoS) due to the driver attempting to access freed memory.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89738.json)\n\n**kernel: usb: gadget: at91_udc: drain polled-VBUS timer/work before udc is freed** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-21.\n\nNot affected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 6\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\nRefer to the advisory for fix availability.","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":208954,"id":"CVE-2026-89738","ts":1790062299007,"field":"cvss","old":"4.1","new":"5.5"},{"seq":203037,"id":"CVE-2026-89738","ts":1789403733450,"field":"cvss","old":"7.8","new":"4.1"},{"seq":203036,"id":"CVE-2026-89738","ts":1789403733450,"field":"severity","old":"high","new":"medium"},{"seq":197686,"id":"CVE-2026-89738","ts":1789384318402,"field":"cvss","old":"4.1","new":"7.8"},{"seq":197685,"id":"CVE-2026-89738","ts":1789384318402,"field":"severity","old":"medium","new":"high"},{"seq":183835,"id":"CVE-2026-89738","ts":1789356677606,"field":"cvss","old":"7.8","new":"4.1"},{"seq":183834,"id":"CVE-2026-89738","ts":1789356677606,"field":"severity","old":"high","new":"medium"},{"seq":153622,"id":"CVE-2026-89738","ts":1789285351582,"field":"cvss","old":null,"new":"7.8"},{"seq":153621,"id":"CVE-2026-89738","ts":1789285351582,"field":"severity","old":"none","new":"high"},{"seq":147514,"id":"CVE-2026-89738","ts":1789270211206,"field":"cvss","old":null,"new":"4.1"},{"seq":147513,"id":"CVE-2026-89738","ts":1789270211206,"field":"severity","old":"none","new":"medium"},{"seq":109268,"id":"CVE-2026-89738","ts":1789183731213,"field":"cvss","old":null,"new":"4.1"},{"seq":109267,"id":"CVE-2026-89738","ts":1789183731213,"field":"severity","old":"none","new":"medium"}]}