{"id":"CVE-2026-89634","title":"kernel: smb: client: fix ALIGN() overflow in symlink_data() error context loop (CVE-2026-89634)","summary":"A flaw was found in the Server Message Block (SMB) client within the Linux kernel. An integer overflow in the ALIGN() function, specifically within the symlink_data() error context loop, can lead to an out-of-bounds read. This issue allows…","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-125","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":"2026-09-14","sourceUpdated":"2026-09-14T19:27:16+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89634"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532080"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89634"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89634"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89634.mbox"},{"url":"https://git.kernel.org/stable/c/2b4a25baa0b936fef6915c0459925077b324ecaf"},{"url":"https://git.kernel.org/stable/c/b89d678f9eafcf8d74885983166ba26b40a04ea0"},{"url":"https://git.kernel.org/stable/c/657372ba6ea50b4474d2a6a610097eae8cd1f3e9"},{"url":"https://git.kernel.org/stable/c/1f824f61d1df52392eaf0b74dfa5659d724fde30"},{"url":"https://git.kernel.org/stable/c/62a3025983c8c735a3c6fc85a59316f31b59af07"},{"url":"https://git.kernel.org/stable/c/62656b024efc21c3230eade1a847f25871c3d2bb"}],"tags":["csaf","vex","red-hat","cve.org","score-dispute"],"epss":0.00702,"epssPercentile":0.51814,"scores":{"vendor":7,"cna":9.1},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89634","body":"## Overview\n\nA flaw was found in the Server Message Block (SMB) client within the Linux kernel. An integer overflow in the ALIGN() function, specifically within the symlink_data() error context loop, can lead to an out-of-bounds read. This issue allows a malicious SMB server to cause a denial of service (DoS) by triggering an infinite loop or potentially disclose sensitive information.\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 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89634.json)\n\n**kernel: smb: client: fix ALIGN() overflow in symlink_data() error context loop** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-14.\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":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":204169,"id":"CVE-2026-89634","ts":1789490235642,"field":"cvss","old":"9.1","new":"7"},{"seq":204168,"id":"CVE-2026-89634","ts":1789490235642,"field":"severity","old":"critical","new":"high"},{"seq":197828,"id":"CVE-2026-89634","ts":1789384320571,"field":"cvss","old":"5.4","new":"9.1"},{"seq":197827,"id":"CVE-2026-89634","ts":1789384320571,"field":"severity","old":"medium","new":"critical"},{"seq":183727,"id":"CVE-2026-89634","ts":1789356677125,"field":"cvss","old":"9.1","new":"5.4"},{"seq":183726,"id":"CVE-2026-89634","ts":1789356677125,"field":"severity","old":"critical","new":"medium"},{"seq":153472,"id":"CVE-2026-89634","ts":1789285350654,"field":"cvss","old":null,"new":"9.1"},{"seq":153471,"id":"CVE-2026-89634","ts":1789285350654,"field":"severity","old":"none","new":"critical"},{"seq":109588,"id":"CVE-2026-89634","ts":1789183732526,"field":"cvss","old":null,"new":"5.4"},{"seq":109587,"id":"CVE-2026-89634","ts":1789183732526,"field":"severity","old":"none","new":"medium"}]}