{"id":"CVE-2026-125393","kind":"vulnerability","aliases":["CVE-2026-125393"],"related":[],"title":"MailEnable Enterprise Premium: IMAP heap overflow lets authenticated users crash mail service","description":"MailEnable Enterprise Premium before 10.62 contains a heap overflow vulnerability in the IMAP X-FB-FETCH command that allows authenticated users to overflow a fixed 0x400-byte heap buffer. Attackers can supply an X-FB-USER address longer than about 1016 bytes, which is formatted without a length check, to crash the IMAP service and cause denial of service.","summary":"MailEnable Enterprise Premium before 10.62 has a heap overflow in the IMAP X-FB-FETCH command, where an oversized X-FB-USER address is written past a fixed 0x400-byte buffer. An authenticated user can crash the IMAP service, causing denial of service.","severity":"high","cvss":7.1,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["imap","mailenable","self-hosted","vendor","windows"],"not_affected_if":["auth-required","non-premium-edition"],"how_to_check":"- Check the installed MailEnable Enterprise Premium version in the MailEnable administration console; unknown if the sources give another method.","fix":"- MailEnable Enterprise Premium: move to `10.62` or later.","status":"open","published_at":"2026-11-10T00:17:13+00:00","first_seen_at":"2026-11-10T00:28:44+00:00","triaged_at":"2026-11-10T00:30:08+00:00","updated_at":"2026-11-10T00:30:08+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-11-10T00:30:08Z","model":"claude-haiku-5-5","output":{"fix":"- MailEnable Enterprise Premium: move to `10.62` or later.","reach":"network","title":"MailEnable Enterprise Premium: IMAP heap overflow lets authenticated users crash mail service","impact":"low","summary":"MailEnable Enterprise Premium before 10.62 has a heap overflow in the IMAP X-FB-FETCH command, where an oversized X-FB-USER address is written past a fixed 0x400-byte buffer. An authenticated user can crash the IMAP service, causing denial of service.","audience":"businesses","category":"vendor","nicknames":[],"who_cares":["mailenable","imap","windows","self-hosted"],"confidence":0.6,"fix_status":"available","needs_auth":"yes","worst_case":"IMAP service crashes, causing denial of service for mail users","analyst_note":"","how_to_check":"- Check the installed MailEnable Enterprise Premium version in the MailEnable administration console; unknown if the sources give another method.","plain_action":"","product_name":"","needs_analyst":false,"not_affected_if":["auth-required","non-premium-edition"],"who_is_affected":"Organisations running MailEnable Enterprise Premium with the IMAP service enabled, where users have valid mailbox credentials. The sources do not say whether other MailEnable editions are affected.","user_interaction":"no","product_ecosystem":"","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000709,"input_tokens":4617,"output_tokens":494,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-125393':15A,18A '-2026':14A,17A '0x400':57B,99C '0x400-byte':56B,98C '10.62':30B,76C '1016':115C 'address':50B,111C 'allow':91C 'attack':103C 'authent':8A,61B,92C 'buffer':59B,102C 'byte':58B,100C,116C 'caus':68B,130C 'check':123C 'command':42B,89C 'contain':77C 'crash':10A,64B,125C 'cve':13A,16A 'denial':69B,131C 'enterpris':2A,27B,73C 'fb':40B,48B,87C,109C 'fetch':41B,88C 'fix':55B,97C 'format':119C 'heap':5A,33B,79C,101C 'host':23B 'imap':4A,19B,37B,66B,84C,127C 'length':122C 'let':7A 'longer':112C 'mail':11A 'mailen':1A,20B,26B,72C 'overflow':6A,34B,80C,95C 'overs':45B 'past':53B 'premium':3A,28B,74C 'self':22B 'self-host':21B 'servic':12A,67B,71B,128C,133C 'suppli':105C 'user':9A,49B,62B,93C,110C 'vendor':24B 'vulner':81C 'window':25B 'without':120C 'written':52B 'x':39B,47B,86C,108C 'x-fb-fetch':38B,85C 'x-fb-user':46B,107C","nicknames":[],"mitigations":[],"who_affected":"Organisations running MailEnable Enterprise Premium with the IMAP service enabled, where users have valid mailbox credentials. The sources do not say whether other MailEnable editions are affected.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["high","imap","mailenable","selfhosted","vendor","windows"],"campaign_type":null,"search_a":"'-125393':15A,18A '-2026':14A,17A 'authent':8A 'crash':10A 'cve':13A,16A 'enterpris':2A 'heap':5A 'imap':4A 'let':7A 'mail':11A 'mailen':1A 'overflow':6A 'premium':3A 'servic':12A 'user':9A","search_b":"'0x400':57B '0x400-byte':56B '10.62':30B 'address':50B 'authent':61B 'buffer':59B 'byte':58B 'caus':68B 'command':42B 'crash':64B 'denial':69B 'enterpris':27B 'fb':40B,48B 'fetch':41B 'fix':55B 'heap':33B 'host':23B 'imap':19B,37B,66B 'mailen':20B,26B 'overflow':34B 'overs':45B 'past':53B 'premium':28B 'self':22B 'self-host':21B 'servic':67B,71B 'user':49B,62B 'vendor':24B 'window':25B 'written':52B 'x':39B,47B 'x-fb-fetch':38B 'x-fb-user':46B","search_c":"'0x400':99C '0x400-byte':98C '10.62':76C '1016':115C 'address':111C 'allow':91C 'attack':103C 'authent':92C 'buffer':102C 'byte':100C,116C 'caus':130C 'check':123C 'command':89C 'contain':77C 'crash':125C 'denial':131C 'enterpris':73C 'fb':87C,109C 'fetch':88C 'fix':97C 'format':119C 'heap':79C,101C 'imap':84C,127C 'length':122C 'longer':112C 'mailen':72C 'overflow':80C,95C 'premium':74C 'servic':128C,133C 'suppli':105C 'user':93C,110C 'vulner':81C 'without':120C 'x':86C,108C 'x-fb-fetch':85C 'x-fb-user':107C","cause_entry":null,"cause_path":null,"disclosures_checked_at":null,"first_public_at":"2026-11-10T00:17:13+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-125393","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-125393","severity":null,"published_at":"2026-11-10T00:17:13+00:00","modified_at":"2026-11-10T00:17:13+00:00","first_seen_at":"2026-11-10T00:28:44+00:00","fetched_at":"2026-11-10T00:28:44+00:00","note":null}],"documents":[{"id":111583,"url":"https://www.vulncheck.com/advisories/mailenable-enterprise-premium-before-10.62-heap-overflow-via-imap-x-fb-fetch","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"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"}