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CVE-2026-89035

7.4, high

MikroTik RouterOS Insufficient Session Expiration Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
7.4, high high CVSS v3.1
EPSS, next 30 days
0.3% higher than 18.7% of scored CVEs
Exploitation
No public evidence
Published
21 Oct 20262 days ago

Description

MikroTik RouterOS through 7.24.5 contains a session token replay vulnerability in the WebFig interface that allows attackers to bypass authentication by replaying captured session tokens across new ECDH sessions. The makeSessionKey function in libucrypto.so generates tokens using fixed salts without incorporating channel-specific or session-specific input, and the user service validates tokens against the login store without verifying channel context, enabling stolen tokens to grant persistent administrative access until the token store is explicitly cleared. This vulnerability extends the impact of CVE-2025-61481, which identified the underlying transport-layer exposure without a corresponding fix.

Details

Vendor
MikroTik
Product
RouterOS
Weakness
CWE-613 (opens in a new tab)
Status
Awaiting analysis
Updated
22 Oct 2026
Assigner
disclosure@vulncheck.com

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

References 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other MikroTik CVEs

Every MikroTik CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-67277 MikroTik RouterOS Missing Authentication for Critical Function Vulnerability KEV EPSS 2% 8.2, high
  • CVE-2026-67279 Mikrotik RouterOS Improper Enforcement of Behavioral Workflow Vulnerability KEV EPSS 1% 6.5, medium
  • CVE-2026-86060 MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command Vulnerability KEV EPSS 6% 9.8, critical
  • CVE-2018-14847 MikroTik Router OS Directory Traversal Vulnerability KEV EPSS 96% 9.1, critical
  • CVE-2018-7445 MikroTik RouterOS Stack-Based Buffer Overflow Vulnerability KEV EPSS 61% 9.8, critical
  • CVE-2026-67278 MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and… EPSS 0.3% 9.1, critical
  • CVE-2026-67276 RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking… EPSS 6% 8.1, high
  • CVE-2026-67281 Mikrotik RouterOS Path Traversal Vulnerability EPSS 0.7% 7.5, high

Beyond this page

Is CVE-2026-89035 in your network?

This page tells you how dangerous CVE-2026-89035 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

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    Detect it if it's exploited

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 23 Oct 2026, not the live upstream state.