{"id":"CVE-2026-103903","revision":"b46203228161492eb8a1469e548ee8e4","records":[{"revision":"b46203228161492eb8a1469e548ee8e4","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-103903","aliases":[],"title":"MikroTik RouterOS WinBox split-principal authentication bypass allows privilege escalation","description":"An incorrect authorization vulnerability in the WinBox\nauthentication flow of MikroTik RouterOS allows a remote authenticated attacker\nwith credentials for a low-privilege account permitted to use WinBox to obtain\nthe authorization policy of a different existing account. The stage-one EC-SRP\nchallenge and proof are verified using the attacker's account, while the\nindependently supplied stage-two username is used to install the target\naccount's privileges. By specifying a higher-privilege account such as admin, a\nlow-privilege user can obtain a full administrative session without knowing the\ntarget account's password and can use that session to increase the privileges\nof the attacker's own account.","state":0,"publishedAt":"2026-10-12T10:37:23.578+00:00","modifiedAt":"2026-10-13T11:57:50.805+00:00","affected":[{"ecosystem":"Vendor product","name":"RouterOS","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"MikroTik\",\n                    \"product\": \"RouterOS\",\n                    \"modules\": [\n                        \"WinBox authentication / user service\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"7.0.0\",\n                            \"lessThan\": \"7.24.5\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"status\": \"unaffected\",\n                            \"version\": \"7.25rc1\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"affected\"\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","score":8.7,"severity":"HIGH"},{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://mikrotik.com/download/changelogs?channelFilter=stable&versionFilter=7.24.5","https://forum.mikrotik.com/t/7-25rc1-testing-is-released/27352","https://br2sec.com/lv/resursi/2026-routeros-winbox-auth-bypass/","https://cvd.cert.lv/disclosed/vuln-all-709639748"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-103903","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-103903","identifiers":["CVE-2026-103903"]},"retained":false,"historicalAffected":[]}],"coverage":[]}