{"id":"CVE-2026-103903","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-103903","generatedAt":"2026-10-28T05:59:55.917Z","title":"An incorrect authorization vulnerability in the WinBox authentication flow of MikroTik RouterOS allows a remote authenticated attacker with credentials for a low-privilege account permitted to use WinBox to obtain the authorization policy of a different…","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.","published":"2026-10-12T11:17:10.000Z","lastModified":"2026-10-16T17:25:58.000Z","status":"Awaiting Analysis","sourceIdentifier":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-863"],"affected":[],"epss":{"score":0.00415,"percentile":0.35587,"date":"2026-10-27","history":[{"date":"2026-10-13","score":0.00415,"percentile":0.33987}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-12T11:17:10.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-12T11:17:09.517Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://br2sec.com/lv/resursi/2026-routeros-winbox-auth-bypass/","source":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"},{"url":"https://cvd.cert.lv/disclosed/vuln-all-709639748","source":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"},{"url":"https://forum.mikrotik.com/t/7-25rc1-testing-is-released/27352","source":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"},{"url":"https://mikrotik.com/download/changelogs?channelFilter=stable&versionFilter=7.24.5","source":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-103903","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}