MikroTik RouterOS Stack Buffer Overflow via TFTP URL Path
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.
CVE-2026-89020
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89020
RouterOS
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "MikroTik",
"product": "RouterOS",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "7.23.4",
"versionType": "semver"
},
{
"status": "affected",
"version": "7.24.0",
"lessThan": "7.24.2",
"versionType": "semver"
}
],
"defaultStatus": "unknown"
}
]- Related CVEs
- CVE-2026-89020
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #5581 · Revision 1
- Added to Heist Feed
- Publisher date