CVE-2026-89020
MikroTik RouterOS Stack Buffer Overflow via TFTP URL Path
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.
INFO
Published Date :
Sept. 14, 2026, 6:02 p.m.
Last Modified :
Sept. 14, 2026, 6:02 p.m.
Remotely Exploit :
Yes !
Source :
VulnCheck
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | MEDIUM | 83251b91-4cc7-4094-a5c7-464a1b83ea10 |
Solution
- Update RouterOS to 7.23.4 (long-term) or 7.24.2 (stable).
- Avoid using crafted TFTP URL paths with /tool fetch.
- Restrict access to /tool fetch command.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-89020 vulnerability anywhere in the article.