CVE-2026-89020

MEDIUM Status: Received

CVSS Scores

CVSS v3.x Base Score
4.3
MEDIUM

Description

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.

Published
September 14, 2026 7:17 PM
Last Modified
September 14, 2026 7:17 PM
Source
[email protected]

Weaknesses (CWE)

CWE-121

References

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