{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-103903","assignerOrgId":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158","state":"PUBLISHED","assignerShortName":"ENISA","dateReserved":"2026-10-01T14:12:50.876Z","datePublished":"2026-10-12T10:37:23.578Z","dateUpdated":"2026-10-13T11:57:50.805Z"},"containers":{"cna":{"providerMetadata":{"orgId":"a6d3dc9e-0591-4a13-bce7-0f5b31ff6158","shortName":"ENISA","dateUpdated":"2026-10-12T10:37:23.578Z"},"title":"MikroTik RouterOS WinBox split-principal authentication bypass allows privilege escalation","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-863","description":"CWE-863 Incorrect Authorization","type":"CWE"}]}],"affected":[{"vendor":"MikroTik","product":"RouterOS","modules":["WinBox authentication / user service"],"versions":[{"status":"affected","version":"7.0.0","lessThan":"7.24.5","versionType":"semver"},{"status":"unaffected","version":"7.25rc1","versionType":"custom"}],"defaultStatus":"affected"}],"descriptions":[{"lang":"en","value":"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.","supportingMedia":[{"type":"text/html","base64":false,"value":"<span>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.</span>"}]}],"references":[{"url":"https://mikrotik.com/download/changelogs?channelFilter=stable&versionFilter=7.24.5","name":"MikroTik RouterOS 7.24.5 stable release notes","tags":["release-notes"]},{"url":"https://forum.mikrotik.com/t/7-25rc1-testing-is-released/27352","tags":["release-notes"]},{"url":"https://br2sec.com/lv/resursi/2026-routeros-winbox-auth-bypass/","tags":["technical-description","third-party-advisory"]},{"url":"https://cvd.cert.lv/disclosed/vuln-all-709639748","tags":["government-resource"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"HIGH","baseScore":8.7,"vectorString":"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"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH","baseSeverity":"HIGH","baseScore":8.8,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}}],"workarounds":[{"lang":"en","value":"Until upgrade, restrict the WinBox service to trusted\nmanagement addresses, remove the winbox policy from low-privilege accounts, or\ndisable WinBox. These measures reduce reachability but do not replace the fix.","supportingMedia":[{"type":"text/html","base64":false,"value":"<span>Until upgrade, restrict the WinBox service to trusted\nmanagement addresses, remove the winbox policy from low-privilege accounts, or\ndisable WinBox. These measures reduce reachability but do not replace the fix.</span>"}]}],"solutions":[{"lang":"en","value":"Upgrade to RouterOS 7.24.5 stable, 7.25rc1 testing, or\na later vendor release containing the fix.","supportingMedia":[{"type":"text/html","base64":false,"value":"<span>Upgrade to RouterOS 7.24.5 stable, 7.25rc1 testing, or\na later vendor release containing the fix.</span>"}]}],"x_generator":{"engine":"Vulnogram 1.0.5"},"source":{"discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-103903","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-13T03:55:34.306578Z"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-13T11:57:50.805Z"}}]}}