{"id":"CVE-2026-45659","aliases":["EUVD-2026-31518","GHSA-w3mh-jmwv-56f3"],"status":"published","title":"Microsoft SharePoint Remote Code Execution Vulnerability","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","severity":{"version":"3.1","score":8.8,"vector":"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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.80242,"percentile":0.99624,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":true,"fix_available":false},"cwes":["CWE-502"],"published":"2026-05-22T22:04:33Z","modified":"2026-08-11T03:55:31Z","kev":{"date_added":"2026-07-01","due_date":"2026-07-04","required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","known_ransomware_use":"Known"},"exploitation":[{"source":"euvd","since":"2026-07-01"},{"source":"kev","since":"2026-07-01"}],"exploits":[{"source":"pocgithub","id":"HORKimhab/CVE-2026-45659","title":"HORKimhab/CVE-2026-45659","date":"2026-05-27","url":"https://github.com/HORKimhab/CVE-2026-45659"}],"products":[{"vendor":"microsoft","product":"microsoft sharepoint enterprise server 2016"},{"vendor":"microsoft","product":"microsoft sharepoint server 2019"},{"vendor":"microsoft","product":"microsoft sharepoint server subscription edition"},{"vendor":"microsoft","product":"sharepoint server"},{"vendor":"microsoft","product":"sharepoint_server"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45659","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45659","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45659"},{"url":"https://github.com/advisories/GHSA-w3mh-jmwv-56f3"}],"sources":{"cve":[{"id":"CVE-2026-45659","title":"Microsoft SharePoint Remote Code Execution Vulnerability","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","status":"published","published":"2026-05-22T22:04:33.517Z","modified":"2026-08-11T03:55:31.769Z","cvss":[{"version":"3.1","score":8.8,"vector":"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","level":"high","assessor":"cna"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T13:46:32.755125Z"}],"euvd":[{"id":"EUVD-2026-31518","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","status":"published","published":"2026-05-22T22:04:33Z","modified":"2026-08-11T03:55:31Z","cvss":[{"version":"3.1","score":8.8,"vector":"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","level":"high"}],"exploited_since":"2026-07-01","updated_at":"2026-11-02T18:02:00.742322Z"}],"ghsa":[{"id":"GHSA-w3mh-jmwv-56f3","title":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to...","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","status":"published","published":"2026-05-26T13:30:23Z","modified":"2026-07-01T21:35:53Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T15:09:10.245383Z"}],"kev":[{"id":"CVE-2026-45659","title":"Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability","description":"Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.","cwes":["CWE-502"],"kev":{"date_added":"2026-07-01","due_date":"2026-07-04","required_action":"Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.","known_ransomware_use":"Known"},"updated_at":"2026-11-02T17:00:15.999436Z"}],"nvd":[{"id":"CVE-2026-45659","description":"Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.","status":"published","published":"2026-05-22T23:16:56.273Z","modified":"2026-07-23T11:10:00.12Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-502"],"updated_at":"2026-11-02T14:12:20.131508Z"}]}}