{"id":"CVE-2026-89653","title":"ceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode\n\nMDSMap export_targets entries are monitor controlled. check_new_map()\nuses each entry as a bit numbe…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 8c823bbab3c24e657469a84db96902ba82d4e8bb","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < c4addccd05bacbef2144b4db14853d0308a218ac","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 736adee11af36e407ed902264f8b2fb5cf94b62f","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 4d298880f82c42383b36946bafde7ccf4d804c9b","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 96c3f5fbb0d5386e7111426f047f98cec4586674","Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < aedc9053d909508a5f56c3f49f885fc030df4730","Linux 5.15"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T19:25:22.176850Z"},"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:50:24.862Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89653","references":[{"url":"https://git.kernel.org/stable/c/3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe"},{"url":"https://git.kernel.org/stable/c/8c823bbab3c24e657469a84db96902ba82d4e8bb"},{"url":"https://git.kernel.org/stable/c/c4addccd05bacbef2144b4db14853d0308a218ac"},{"url":"https://git.kernel.org/stable/c/736adee11af36e407ed902264f8b2fb5cf94b62f"},{"url":"https://git.kernel.org/stable/c/4d298880f82c42383b36946bafde7ccf4d804c9b"},{"url":"https://git.kernel.org/stable/c/96c3f5fbb0d5386e7111426f047f98cec4586674"},{"url":"https://git.kernel.org/stable/c/aedc9053d909508a5f56c3f49f885fc030df4730"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89653.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89653"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532386"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89653"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89653"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89653.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00502,"epssPercentile":0.42784,"scores":{"cna":9.8,"vendor":8.1},"ingestedAt":"2026-09-14T15:23:07.450Z","slug":"CVE-2026-89653","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nceph: reject export_targets ranks >= CEPH_MAX_MDS in mdsmap decode\n\nMDSMap export_targets entries are monitor controlled. check_new_map()\nuses each entry as a bit number in a fixed stack bitmap, so a rank\noutside the protocol namespace can make set_bit() write past the end of\nthe array.\n\nReject ranks outside CEPH_MAX_MDS while decoding the map. Do not\nvalidate against possible_max_rank here because maps may legitimately\nreference ranks beyond a temporarily reduced max_mds.\n\n## Affected\n\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 3740c88ca9cb2210a8dbdd55ea4cec119fbe86fe`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 8c823bbab3c24e657469a84db96902ba82d4e8bb`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < c4addccd05bacbef2144b4db14853d0308a218ac`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 736adee11af36e407ed902264f8b2fb5cf94b62f`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 4d298880f82c42383b36946bafde7ccf4d804c9b`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < 96c3f5fbb0d5386e7111426f047f98cec4586674`\n- `Linux >= d517b3983dd3106ca92d6c5d0d09415a4a09481c < aedc9053d909508a5f56c3f49f885fc030df4730`\n- `Linux 5.15`\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** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-05 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89653.json)","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":223259,"id":"CVE-2026-89653","ts":1792180033398,"field":"cvss","old":"8.1","new":"9.8"},{"seq":223258,"id":"CVE-2026-89653","ts":1792180033398,"field":"severity","old":"high","new":"critical"},{"seq":206390,"id":"CVE-2026-89653","ts":1789663224293,"field":"cvss","old":"7","new":"8.1"},{"seq":205433,"id":"CVE-2026-89653","ts":1789576712324,"field":"cvss","old":"9.8","new":"7"},{"seq":205432,"id":"CVE-2026-89653","ts":1789576712324,"field":"severity","old":"critical","new":"high"},{"seq":197791,"id":"CVE-2026-89653","ts":1789384318871,"field":"cvss","old":"7.5","new":"9.8"},{"seq":197790,"id":"CVE-2026-89653","ts":1789384318871,"field":"severity","old":"high","new":"critical"},{"seq":183373,"id":"CVE-2026-89653","ts":1789356675094,"field":"cvss","old":"9.8","new":"7.5"},{"seq":183372,"id":"CVE-2026-89653","ts":1789356675094,"field":"severity","old":"critical","new":"high"},{"seq":153504,"id":"CVE-2026-89653","ts":1789285350950,"field":"cvss","old":null,"new":"9.8"},{"seq":153503,"id":"CVE-2026-89653","ts":1789285350950,"field":"severity","old":"none","new":"critical"},{"seq":147273,"id":"CVE-2026-89653","ts":1789270206116,"field":"cvss","old":null,"new":"7.5"},{"seq":147272,"id":"CVE-2026-89653","ts":1789270206116,"field":"severity","old":"none","new":"high"},{"seq":109030,"id":"CVE-2026-89653","ts":1789183730029,"field":"cvss","old":null,"new":"7.5"},{"seq":109029,"id":"CVE-2026-89653","ts":1789183730029,"field":"severity","old":"none","new":"high"}]}