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 existing account. The stage-one EC-SRP challenge and proof are verified using the attacker's account, while the independently supplied stage-two username is used to install the target account's privileges. By specifying a higher-privilege account such as admin, a low-privilege user can obtain a full administrative session without knowing the target account's password and can use that session to increase the privileges of the attacker's own account.
History

Tue, 13 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Mon, 12 Oct 2026 12:45:00 +0000

Type Values Removed Values Added
First Time appeared Mikrotik
Mikrotik routeros
Vendors & Products Mikrotik
Mikrotik routeros

Mon, 12 Oct 2026 11:00:00 +0000

Type Values Removed Values Added
Description 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 existing account. The stage-one EC-SRP challenge and proof are verified using the attacker's account, while the independently supplied stage-two username is used to install the target account's privileges. By specifying a higher-privilege account such as admin, a low-privilege user can obtain a full administrative session without knowing the target account's password and can use that session to increase the privileges of the attacker's own account.
Title MikroTik RouterOS WinBox split-principal authentication bypass allows privilege escalation
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, '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'}


cve-icon MITRE

Status: PUBLISHED

Assigner: ENISA

Published: 2026-10-12T10:37:23.578Z

Updated: 2026-10-13T11:57:50.805Z

Reserved: 2026-10-01T14:12:50.876Z

Link: CVE-2026-103903

cve-icon Vulnrichment

Updated: 2026-10-13T11:52:14.071Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-12T11:17:09.517

Modified: 2026-10-16T17:25:57.940

Link: CVE-2026-103903

cve-icon Redhat

No data.