{"id":"CVE-2026-123391","kind":"vulnerability","aliases":["CVE-2026-123391"],"related":[],"title":"Microsoft SharePoint: authorized users can gain higher privileges over network","description":"Incorrect authorization in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.","summary":"Microsoft Office SharePoint has an incorrect authorization check that lets a logged-in user raise their privileges across the network. An attacker who already holds a valid account can gain rights beyond what they were granted.","severity":"high","cvss":8.8,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["microsoft-office","on-premises","sharepoint","vendor"],"not_affected_if":["no-sharepoint","sharepoint-online-only"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:20:43+00:00","first_seen_at":"2026-11-10T19:25:12+00:00","triaged_at":"2026-11-10T19:26:20+00:00","updated_at":"2026-11-10T19:26:20+00:00","category":"vendor","confidence":0.5,"triage":{"at":"2026-11-10T19:26:20Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft SharePoint: authorized users can gain higher privileges over network","impact":"high","summary":"Microsoft Office SharePoint has an incorrect authorization check that lets a logged-in user raise their privileges across the network. An attacker who already holds a valid account can gain rights beyond what they were granted.","audience":"businesses","category":"vendor","nicknames":[],"who_cares":["sharepoint","microsoft-office","on-premises"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"authorized user gains elevated privileges over the network","analyst_note":"Find Microsoft's advisory for CVE-2026-123391 to confirm affected SharePoint versions, fixed builds and whether SharePoint Online is affected.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["no-sharepoint","sharepoint-online-only"],"who_is_affected":"Organizations running Microsoft SharePoint on-premises servers where users hold valid accounts. The sources do not state which SharePoint versions or configurations are affected, so teams should confirm against Microsoft's advisory. Organizations using only SharePoint Online may not be affected, but the sources do not confirm this.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000694,"input_tokens":4496,"output_tokens":489,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find Microsoft's advisory for CVE-2026-123391 to confirm affected SharePoint versions, fixed builds and whether SharePoint Online is affected.","search":"'-123391':13A,16A '-2026':12A,15A 'account':53B 'across':43B 'allow':68C 'alreadi':49B 'attack':47B,71C 'author':3A,31B,63C,70C 'beyond':57B 'check':32B 'cve':11A,14A 'elev':73C 'gain':6A,55B 'grant':61B 'higher':7A 'hold':50B 'incorrect':30B,62C 'let':34B 'log':37B 'logged-in':36B 'microsoft':1A,18B,25B,65C 'microsoft-offic':17B 'network':10A,45B,77C 'offic':19B,26B,66C 'on-premis':20B 'premis':22B 'privileg':8A,42B,74C 'rais':40B 'right':56B 'sharepoint':2A,23B,27B,67C 'user':4A,39B 'valid':52B 'vendor':24B","nicknames":[],"mitigations":[],"who_affected":"Organizations running Microsoft SharePoint on-premises servers where users hold valid accounts. The sources do not state which SharePoint versions or configurations are affected, so teams should confirm against Microsoft's advisory. Organizations using only SharePoint Online may not be affected, but the sources do not confirm this.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","microsoftoffice","onpremises","sharepoint","vendor"],"campaign_type":null,"search_a":"'-123391':13A,16A '-2026':12A,15A 'author':3A 'cve':11A,14A 'gain':6A 'higher':7A 'microsoft':1A 'network':10A 'privileg':8A 'sharepoint':2A 'user':4A","search_b":"'account':53B 'across':43B 'alreadi':49B 'attack':47B 'author':31B 'beyond':57B 'check':32B 'gain':55B 'grant':61B 'hold':50B 'incorrect':30B 'let':34B 'log':37B 'logged-in':36B 'microsoft':18B,25B 'microsoft-offic':17B 'network':45B 'offic':19B,26B 'on-premis':20B 'premis':22B 'privileg':42B 'rais':40B 'right':56B 'sharepoint':23B,27B 'user':39B 'valid':52B 'vendor':24B","search_c":"'allow':68C 'attack':71C 'author':63C,70C 'elev':73C 'incorrect':62C 'microsoft':65C 'network':77C 'offic':66C 'privileg':74C 'sharepoint':67C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:20:43+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123391","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123391","severity":null,"published_at":"2026-11-10T19:20:43+00:00","modified_at":"2026-11-10T19:20:43+00:00","first_seen_at":"2026-11-10T19:25:12+00:00","fetched_at":"2026-11-10T19:25:12+00:00","note":null}],"documents":[],"disclosures":[],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}