Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-103903— MikroTik RouterOS WinBox split-principal authentication bypass allows privilege escalation

Quick assessment

Affected
MikroTik RouterOS
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

MikroTik RouterOS 的 WinBox 认证流程中存在一个错误的授权漏洞，允许经过身份验证的远程攻击者利用具有低权限且被允许使用 WinBox 的账户凭据，获取其他已有账户的授权策略。在此过程中，第一阶段 EC-SRP 挑战与证明通过攻击者自身的账户进行验证，而独立提供的第二阶段用户名用于安装目标账户的权限。通过指定高权限账户（例如 admin），低权限用户可以在不知道目标账户密码的情况下获得完整的管理员会话，并利用该会话提升攻击者自身账户的权限。

CVSS 8.8 · High EPSS 0.41% · P34

Affected Version Matrix 2

VendorProduct Version RangeStatus
MikroTik RouterOS 7.0.0< 7.24.5 affected
7.25rc1 unaffected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-103903

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
MikroTik RouterOS WinBox split-principal authentication bypass allows privilege escalation
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
授权机制不正确
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
MikroTik RouterOS 7.0.0 ~ 7.24.5 -

II. Public POCs for CVE-2026-103903

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-103903

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-103903 (1)

Security Blog Posts for CVE-2026-103903 (1)

Other References for CVE-2026-103903 (1)

Other References for CVE-2026-103903 (1)

IV. Related Vulnerabilities

Same product: RouterOS
Same vendor: MikroTik
Same weakness: CWE-863

V. Comments for CVE-2026-103903

No comments yet

Leave a comment