{"id":"CVE-2026-89721","title":"kernel: phy: rockchip-samsung-dcphy: fix out-of-range max_register (CVE-2026-89721)","summary":"A flaw was found in the Linux kernel's `phy: rockchip-samsung-dcphy` component. A local attacker with access to the `regmap debugfs` interface could trigger an out-of-bounds read by attempting to dump registers. This occurs because the `ma…","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-125","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","affected":["openshift_container_platform 4"],"published":"2026-09-11","updated":"2026-09-21","sourceUpdated":"2026-09-21T17:24:41+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89721.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89721.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89721"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532300"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89721"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89721"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89721.mbox"},{"url":"https://git.kernel.org/stable/c/14afe18655c0951f4f85898f761bf92264e65ccd"},{"url":"https://git.kernel.org/stable/c/4486e75ba647bd8b98fc1f053101b40caceeed4b"},{"url":"https://git.kernel.org/stable/c/c1a62f9dcf531d56c56da2e4435386b6d264c69f"}],"tags":["csaf","vex","red-hat","cve.org"],"epss":0.00206,"epssPercentile":0.09482,"ingestedAt":"2026-09-14T11:11:19.885Z","slug":"CVE-2026-89721","body":"## Overview\n\nA flaw was found in the Linux kernel's `phy: rockchip-samsung-dcphy` component. A local attacker with access to the `regmap debugfs` interface could trigger an out-of-bounds read by attempting to dump registers. This occurs because the `max_register` value is incorrectly set, causing the system to read beyond the allocated memory region. Successful exploitation leads to a kernel crash (oops) and a subsequent deadlock of physical layer (PHY) operations, resulting in a denial of service.\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-2026-89721.json)\n\n**kernel: phy: rockchip-samsung-dcphy: fix out-of-range max_register** — 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":208962,"id":"CVE-2026-89721","ts":1790062300770,"field":"cvss","old":"4.1","new":"5.5"},{"seq":204000,"id":"CVE-2026-89721","ts":1789490230986,"field":"cvss","old":null,"new":"4.1"},{"seq":203999,"id":"CVE-2026-89721","ts":1789490230986,"field":"severity","old":"none","new":"medium"},{"seq":147410,"id":"CVE-2026-89721","ts":1789270210801,"field":"cvss","old":null,"new":"4.1"},{"seq":147409,"id":"CVE-2026-89721","ts":1789270210801,"field":"severity","old":"none","new":"medium"},{"seq":109178,"id":"CVE-2026-89721","ts":1789183730615,"field":"cvss","old":null,"new":"4.1"},{"seq":109177,"id":"CVE-2026-89721","ts":1789183730615,"field":"severity","old":"none","new":"medium"}]}