{"id":"CVE-2026-89641","title":"kernel: cifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size() (CVE-2026-89641)","summary":"A flaw was found in the Linux kernel's Common Internet File System (CIFS) module. This vulnerability, a use-after-free, occurs in the `cifs_file_set_size()` function. When a file's size is being modified, a critical system resource (tcon o…","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-825","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","affected":["enterprise_linux 10","enterprise_linux 9","openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-15","sourceUpdated":"2026-09-15T06:19:15+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89641.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89641.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89641"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532505"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89641"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89641"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89641.mbox"},{"url":"https://git.kernel.org/stable/c/4bea15d9c7683218f57b8c1f5f0aa75cab76af8d"},{"url":"https://git.kernel.org/stable/c/4f18c9e7ee464aaae5cd9fccdb943b3fcb4655d4"},{"url":"https://git.kernel.org/stable/c/b96db32fed8dfb2478d7c208f89bf383beed1535"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.0014,"epssPercentile":0.03681,"scores":{"vendor":4.7,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89641","body":"## Overview\n\nA flaw was found in the Linux kernel's Common Internet File System (CIFS) module. This vulnerability, a use-after-free, occurs in the `cifs_file_set_size()` function. When a file's size is being modified, a critical system resource (tcon object) can be released too early but then accessed again. A local attacker could exploit this to cause a system crash, leading to a Denial of Service (DoS), or potentially execute unauthorized code.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89641.json)\n\n**kernel: cifs: clear tcon after cifsFileInfo_put() in cifs_file_set_size()** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-15.\n\nAffected:\n\n- Red Hat Enterprise Linux 10\n- Red Hat Enterprise Linux 9\n- Red Hat OpenShift Container Platform 4\n\nNo fix planned:\n\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 6\n- Red Hat Enterprise Linux 7\n- Red Hat Enterprise Linux 8\n- Red Hat OpenShift Container Platform 4\n\n## Remediation\n\nAffected","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":203942,"id":"CVE-2026-89641","ts":1789490230693,"field":"cvss","old":"4.7","new":"7"},{"seq":203941,"id":"CVE-2026-89641","ts":1789490230693,"field":"severity","old":"medium","new":"high"},{"seq":203005,"id":"CVE-2026-89641","ts":1789403733316,"field":"cvss","old":"7.8","new":"4.7"},{"seq":203004,"id":"CVE-2026-89641","ts":1789403733316,"field":"severity","old":"high","new":"medium"},{"seq":197813,"id":"CVE-2026-89641","ts":1789384320508,"field":"cvss","old":"4.7","new":"7.8"},{"seq":197812,"id":"CVE-2026-89641","ts":1789384320508,"field":"severity","old":"medium","new":"high"},{"seq":183719,"id":"CVE-2026-89641","ts":1789356677092,"field":"cvss","old":"7.8","new":"4.7"},{"seq":183718,"id":"CVE-2026-89641","ts":1789356677092,"field":"severity","old":"high","new":"medium"},{"seq":153486,"id":"CVE-2026-89641","ts":1789285350711,"field":"cvss","old":null,"new":"7.8"},{"seq":153485,"id":"CVE-2026-89641","ts":1789285350711,"field":"severity","old":"none","new":"high"},{"seq":147145,"id":"CVE-2026-89641","ts":1789270196797,"field":"cvss","old":null,"new":"4.7"},{"seq":147144,"id":"CVE-2026-89641","ts":1789270196797,"field":"severity","old":"none","new":"medium"},{"seq":108896,"id":"CVE-2026-89641","ts":1789183729447,"field":"cvss","old":null,"new":"4.7"},{"seq":108895,"id":"CVE-2026-89641","ts":1789183729447,"field":"severity","old":"none","new":"medium"}]}