CVE-2026-89020

MikroTik RouterOS before 7.23.4 (long-term) and 7.24.2 (stable) contains a stack-based buffer overflow vulnerability in the mtget binary's TFTP RRQ builder function that allows authenticated users to crash the mtget worker process by supplying a URL path of 507 bytes or more to the /tool fetch command; the first write outside the 528-byte buffer occurs at 505 bytes. Attackers can trigger the overflow by issuing a fetch command with a crafted tftp:// URL path, which causes an unbounded rep movsb instruction to overwrite saved registers at a deterministic offset, crashing the process without requiring a reachable TFTP server or elevated privileges beyond read-only group membership.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
https://www.vulncheck.com/advisories/mikrotik-routeros-stack-buffer-overflow-via-tftp-url-path

Configurations

No configuration.

History

16 Sep 2026, 14:17

Type	Values Removed	Values Added
References	~~{'url': 'https://mikrotik.com/supportsec/september-2026-vulnerability', 'source': 'disclosure@vulncheck.com'}~~	() https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 - () https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 -

Information

Published : 2026-09-14 19:17

Updated : 2026-09-16 17:18

NVD link : CVE-2026-89020

Mitre link : CVE-2026-89020

CVE.ORG link : CVE-2026-89020

JSON object : View

Products Affected

No product.

CWE

CWE-121

Stack-based Buffer Overflow

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