{"id":"CVE-2026-89570","title":"cxl/mce: Make the MCE notifier per-region","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mce: Make the MCE notifier per-region\n\nFlavien Solt reported lifetime issues with the CXL MCE notifier, which\ncan lead to NULL dereferences and use-after-free in th…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-476"],"vendor":"Linux","product":"Linux","affected":["Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 5563db13c9528a56c7161260ec75ec8690dc5608","Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 491d8c9ac98d55073bda778f88a5248d4cce3fa0","Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 775d0f4558f4cec0ee0c8966595d1add1791f36e","Linux 6.15"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:49:03.602Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89570","references":[{"url":"https://git.kernel.org/stable/c/5563db13c9528a56c7161260ec75ec8690dc5608"},{"url":"https://git.kernel.org/stable/c/491d8c9ac98d55073bda778f88a5248d4cce3fa0"},{"url":"https://git.kernel.org/stable/c/775d0f4558f4cec0ee0c8966595d1add1791f36e"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89570.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89570"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532510"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89570"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89570"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89570.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00168,"epssPercentile":0.06143,"scores":{"cna":7.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.474Z","slug":"CVE-2026-89570","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncxl/mce: Make the MCE notifier per-region\n\nFlavien Solt reported lifetime issues with the CXL MCE notifier, which\ncan lead to NULL dereferences and use-after-free in the MCE handler.\nThe notifier was registered per memory device and stored in 'struct\ncxl_memdev_state', even though it only needs the region state (the\nregion's SPA range and its extended linear cache size).\n\nInstead of keeping the memory device and endpoint alive, the correct fix\nis to move the notifier into 'struct cxl_region' and register it from\ncxl_region_probe() as it should be a per-region notifier. Setup the\nregistration to only happen for regions that have an extended linear\ncache as that is the only current usage.\n\nRemove cxl_port_get_spa_cache_alias() as it is now dead code.\n\n[ dj: Update dev_warn() when notifier fails due to kconfig. (Ben) ]\n\n## Affected\n\n- `Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 5563db13c9528a56c7161260ec75ec8690dc5608`\n- `Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 491d8c9ac98d55073bda778f88a5248d4cce3fa0`\n- `Linux >= 516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 775d0f4558f4cec0ee0c8966595d1add1791f36e`\n- `Linux 6.15`\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 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89570.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224709,"id":"CVE-2026-89570","ts":1792401483663,"field":"cvss","old":"7","new":"7.8"},{"seq":203939,"id":"CVE-2026-89570","ts":1789490229326,"field":"cvss","old":"4.1","new":"7"},{"seq":203938,"id":"CVE-2026-89570","ts":1789490229326,"field":"severity","old":"medium","new":"high"},{"seq":202879,"id":"CVE-2026-89570","ts":1789403732782,"field":"cvss","old":"7.8","new":"4.1"},{"seq":202878,"id":"CVE-2026-89570","ts":1789403732782,"field":"severity","old":"high","new":"medium"},{"seq":197912,"id":"CVE-2026-89570","ts":1789384320917,"field":"cvss","old":"4.1","new":"7.8"},{"seq":197911,"id":"CVE-2026-89570","ts":1789384320917,"field":"severity","old":"medium","new":"high"},{"seq":183469,"id":"CVE-2026-89570","ts":1789356675493,"field":"cvss","old":"7.8","new":"4.1"},{"seq":183468,"id":"CVE-2026-89570","ts":1789356675493,"field":"severity","old":"high","new":"medium"},{"seq":153384,"id":"CVE-2026-89570","ts":1789285350298,"field":"cvss","old":null,"new":"7.8"},{"seq":153383,"id":"CVE-2026-89570","ts":1789285350298,"field":"severity","old":"none","new":"high"},{"seq":147097,"id":"CVE-2026-89570","ts":1789270195157,"field":"cvss","old":null,"new":"4.1"},{"seq":147096,"id":"CVE-2026-89570","ts":1789270195157,"field":"severity","old":"none","new":"medium"},{"seq":108852,"id":"CVE-2026-89570","ts":1789183729257,"field":"cvss","old":null,"new":"4.1"},{"seq":108851,"id":"CVE-2026-89570","ts":1789183729257,"field":"severity","old":"none","new":"medium"}]}