{"id":"CVE-2026-118157","kind":"vulnerability","aliases":["CVE-2026-118157"],"related":[],"title":"Microsoft Exchange Server: weak authentication lets an authorized user gain privileges","description":"Weak authentication in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.","summary":"Microsoft Exchange Server has weak authentication that lets an attacker who already holds a valid account over the network raise their privileges. The sources give no fixed version, no exploitation evidence, and no further technical detail.","severity":"high","cvss":7.2,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["exchange-server","microsoft-exchange","on-premises","vendor"],"not_affected_if":["exchange-online"],"how_to_check":null,"fix":null,"status":"open","published_at":"2026-11-10T19:19:37+00:00","first_seen_at":"2026-11-10T19:24:49+00:00","triaged_at":"2026-11-10T19:47:48+00:00","updated_at":"2026-11-10T19:47:48+00:00","category":"vendor","confidence":0.5,"triage":{"at":"2026-11-10T19:47:48Z","model":"claude-haiku-5-5","output":{"fix":"unknown","reach":"network","title":"Microsoft Exchange Server: weak authentication lets an authorized user gain privileges","impact":"high","summary":"Microsoft Exchange Server has weak authentication that lets an attacker who already holds a valid account over the network raise their privileges. The sources give no fixed version, no exploitation evidence, and no further technical detail.","audience":"businesses","category":"vendor","nicknames":[],"who_cares":["exchange-server","microsoft-exchange","on-premises"],"confidence":0.5,"fix_status":"unknown","needs_auth":"yes","worst_case":"authenticated user gains higher privileges over the network","analyst_note":"Find Microsoft's advisory for CVE-2026-118157 to confirm affected Exchange versions, fixed builds, and any mitigation; the NVD entry gives none.","how_to_check":"- unknown","plain_action":"","product_name":"","needs_analyst":true,"not_affected_if":["exchange-online"],"who_is_affected":"Organizations running Microsoft Exchange Server on-premises are the ones exposed, since the flaw is in the server rather than a library. Attackers need a valid account first, so mailboxes and directories with many accounts carry more risk. The sources do not state which Exchange versions or configurations are affected, so teams should check Microsoft's advisory before deciding who can skip it.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000702,"input_tokens":4490,"output_tokens":506,"severity_before":"high"},"analyst_status":"queued","analyst_note":"Find Microsoft's advisory for CVE-2026-118157 to confirm affected Exchange versions, fixed builds, and any mitigation; the NVD entry gives none.","search":"'-118157':14A,17A '-2026':13A,16A 'account':43B 'allow':70C 'alreadi':39B 'attack':37B,73C 'authent':5A,33B,65C 'author':8A,72C 'cve':12A,15A 'detail':63B 'elev':75C 'evid':58B 'exchang':2A,19B,23B,29B,68C 'exchange-serv':18B 'exploit':57B 'fix':54B 'gain':10A 'give':52B 'hold':40B 'let':6A,35B 'microsoft':1A,22B,28B,67C 'microsoft-exchang':21B 'network':46B,79C 'on-premis':24B 'premis':26B 'privileg':11A,49B,76C 'rais':47B 'server':3A,20B,30B,69C 'sourc':51B 'technic':62B 'user':9A 'valid':42B 'vendor':27B 'version':55B 'weak':4A,32B,64C","nicknames":[],"mitigations":[],"who_affected":"Organizations running Microsoft Exchange Server on-premises are the ones exposed, since the flaw is in the server rather than a library. Attackers need a valid account first, so mailboxes and directories with many accounts carry more risk. The sources do not state which Exchange versions or configurations are affected, so teams should check Microsoft's advisory before deciding who can skip it.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"none","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["exchangeserver","high","microsoftexchange","onpremises","vendor"],"campaign_type":null,"search_a":"'-118157':14A,17A '-2026':13A,16A 'authent':5A 'author':8A 'cve':12A,15A 'exchang':2A 'gain':10A 'let':6A 'microsoft':1A 'privileg':11A 'server':3A 'user':9A 'weak':4A","search_b":"'account':43B 'alreadi':39B 'attack':37B 'authent':33B 'detail':63B 'evid':58B 'exchang':19B,23B,29B 'exchange-serv':18B 'exploit':57B 'fix':54B 'give':52B 'hold':40B 'let':35B 'microsoft':22B,28B 'microsoft-exchang':21B 'network':46B 'on-premis':24B 'premis':26B 'privileg':49B 'rais':47B 'server':20B,30B 'sourc':51B 'technic':62B 'valid':42B 'vendor':27B 'version':55B 'weak':32B","search_c":"'allow':70C 'attack':73C 'authent':65C 'author':72C 'elev':75C 'exchang':68C 'microsoft':67C 'network':79C 'privileg':76C 'server':69C 'weak':64C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T19:19:37+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","cvss_by":"secure@microsoft.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-118157","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-118157","severity":null,"published_at":"2026-11-10T19:19:37+00:00","modified_at":"2026-11-10T19:19:37+00:00","first_seen_at":"2026-11-10T19:24:49+00:00","fetched_at":"2026-11-10T19:24:49+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"}