{"id":"CVE-2026-66805","title":"Microsoft SharePoint Server Remote Code Execution Vulnerability","summary":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","cvssSource":"cna","cwe":["CWE-502","CWE-79"],"vendor":"Microsoft","product":"Microsoft SharePoint Server Subscription Edition","affected":["sharepoint_server_subscription_edition >= 16.0.0 < 16.0.20326.20190"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-08-07T00:00:00+00:00"},"published":"2026-08-11","updated":"2026-10-21","sourceUpdated":"2026-10-21T20:54:40.617Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-66805","references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66805","label":"Microsoft SharePoint Server Remote Code Execution Vulnerability"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-66805.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-66805"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2508666"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-66805"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-66805"},{"url":"https://issues.redhat.com/browse/ACM-38692"},{"url":"https://access.redhat.com/errata/RHSA-2026:60387"},{"url":"https://access.redhat.com/errata/RHSA-2026:60390"},{"url":"https://access.redhat.com/errata/RHSA-2026:60388"},{"url":"https://access.redhat.com/errata/RHSA-2026:54427"},{"url":"https://access.redhat.com/errata/RHSA-2026:60391"},{"url":"https://access.redhat.com/errata/RHSA-2026:60386"},{"url":"https://access.redhat.com/errata/RHSA-2026:54432"},{"url":"https://access.redhat.com/errata/RHSA-2026:57194"},{"url":"https://access.redhat.com/errata/RHSA-2026:59593"},{"url":"https://access.redhat.com/errata/RHSA-2026:59579"},{"url":"https://access.redhat.com/errata/RHSA-2026:59558"},{"url":"https://access.redhat.com/errata/RHSA-2026:59559"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.02044,"epssPercentile":0.81074,"patched":["advanced_cluster_management_for_kubernetes 2.11","advanced_cluster_management_for_kubernetes 2.13","advanced_cluster_management_for_kubernetes 2.14","advanced_cluster_management_for_kubernetes 2.15","advanced_cluster_management_for_kubernetes 2.16","advanced_cluster_management_for_kubernetes 2.17","multicluster_engine_for_kubernetes 2.10","multicluster_engine_for_kubernetes 2.11","multicluster_engine_for_kubernetes 2.17","multicluster_engine_for_kubernetes 2.6","multicluster_engine_for_kubernetes 2.8","multicluster_engine_for_kubernetes 2.9"],"scores":{"cna":8.8,"vendor":8},"ingestedAt":"2026-09-08T18:07:34.888Z","slug":"CVE-2026-66805","body":"## Overview\n\nDeserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.\n\n## Affected\n\n- `sharepoint_server_subscription_edition >= 16.0.0 < 16.0.20326.20190`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:60387** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.11 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60387)\n- **RHSA-2026:60390** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.13 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60390)\n- **RHSA-2026:60388** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.14 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60388)\n- **RHSA-2026:54427** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.15 · released 2026-08-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:54427)\n- **RHSA-2026:60391** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.16 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60391)\n- **RHSA-2026:60386** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.17 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60386)\n- **RHSA-2026:54432** · Red Hat · fixed in: multicluster engine for Kubernetes 2.10 · released 2026-08-12 · [advisory](https://access.redhat.com/errata/RHSA-2026:54432)\n- **RHSA-2026:57194** · Red Hat · fixed in: multicluster engine for Kubernetes 2.11 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:57194)\n- **RHSA-2026:59593** · Red Hat · fixed in: multicluster engine for Kubernetes 2.17 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59593)\n- **RHSA-2026:59579** · Red Hat · fixed in: multicluster engine for Kubernetes 2.6 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59579)\n- **RHSA-2026:59558** · Red Hat · fixed in: multicluster engine for Kubernetes 2.8 · released 2026-08-25 · [advisory](https://access.redhat.com/errata/RHSA-2026:59558)","depth":"twilight","depthScore":49,"depthScoreParts":{"impact":48.4,"likelihood":0.4,"exploitation":0,"ransomware":0},"changes":[{"seq":211170,"id":"CVE-2026-66805","ts":1790367529740,"field":"cvss","old":"8","new":"8.8"},{"seq":210687,"id":"CVE-2026-66805","ts":1790322194197,"field":"cvss","old":"8.8","new":"8"}]}