{"id":"CVE-2026-89020","state":"PUBLISHED","title":"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.","publishedAt":"2026-09-14T18:02:58.553Z","updatedAt":"2026-10-01T15:21:49.004Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["MikroTik RouterOS"],"affected":[{"vendor":"MikroTik","product":"RouterOS","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"7.23.4","versionType":"semver"},{"version":"7.24.0","status":"affected","lessThan":"7.24.2","versionType":"semver"}]}],"references":["https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800","https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801","https://www.vulncheck.com/advisories/mikrotik-routeros-stack-buffer-overflow-via-tftp-url-path"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89020.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89020","state":"PUBLISHED","datePublished":"2026-09-14T18:02:58.553Z","dateUpdated":"2026-10-01T15:21:49.004Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-09-10T16:23:54.471Z"},"containers":{"cna":{"title":"MikroTik RouterOS Stack Buffer Overflow via TFTP URL Path","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"MikroTik","product":"RouterOS","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"7.23.4","versionType":"semver"},{"version":"7.24.0","status":"affected","lessThan":"7.24.2","versionType":"semver"}]}],"references":[{"url":"https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800","name":"7.24.2 Release Notes","tags":["patch","release-notes"]},{"url":"https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801","tags":["release-notes","patch"],"name":"7.23.4 Release Notes"},{"url":"https://www.vulncheck.com/advisories/mikrotik-routeros-stack-buffer-overflow-via-tftp-url-path","tags":["third-party-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","subConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","subIntegrityImpact":"NONE","vulnAvailabilityImpact":"LOW","subAvailabilityImpact":"NONE","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"MEDIUM","baseScore":5.3,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}},{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW","version":"3.1","baseSeverity":"MEDIUM","baseScore":4.3,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"Stack-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-01T15:21:49.004Z"},"datePublic":"2026-09-03T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*","versionEndExcluding":"7.23.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:mikrotik:routeros:*:*:*:*:*:*:*:*","versionStartIncluding":"7.24.0","versionEndExcluding":"7.24.2"}]}]}],"credits":[{"lang":"en","value":"Kazuma Matsumoto, a security researcher at GMO Cybersecurity by IERAE, Inc.","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"vulncheck"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T16:07:48.174278Z","id":"CVE-2026-89020","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T16:07:59.845Z"}}]}}}