{"schemaVersion":3,"id":"CVE-2026-67278","aliases":[],"status":"published","duplicateOf":null,"title":"TLS server impersonation possible in Mikrotik RouterOS","description":"MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and SSH host-key authentication. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use the root’s public certificate - without its private key - to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation. The same permissive verification also undermines RSA-based SSH authentication.\n\n\n\nThis issue affects only 7.x branch was fixed in versions: 7.23.6 (Long-term) and 7.24.3 (Stable).\nReleases 7.23.4 and 7.24.2 included an incomplete fix.","dates":{"published":"2026-09-05T20:00:57.258Z","modified":"2026-09-17T14:20:12.715Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":9.1,"severity":"critical","version":"3.1","versionLabel":"v3.1","source":"NVD","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":6.3,"severity":"medium","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","score":6.3,"severity":"medium","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00252,"percentile":0.15737,"severity":"low","asOf":"2026-10-22T00:00:00.000Z","change":{"pp":0.07200000000000001,"baselineDate":"2026-09-22T00:00:00.000Z","baselineScore":0.0018},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00155,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00155,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00155,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00155,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00278,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00278,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-22T00:00:00.000Z","score":0.00252,"percentile":0.15737}],"last30":[{"date":"2026-09-22T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.0018,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00278,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00278,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00252,"percentile":null},{"date":"2026-10-22T00:00:00.000Z","score":0.00252,"percentile":0.15737}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[{"id":"REF_F219796D3E196329","name":"Exploit Reference (npratley.net)","source":"reference","url":"https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/","maturity":"unknown","reliabilityScore":0.2,"verified":false,"type":null,"platforms":[],"requiresAuth":null,"exploitdb":null,"metasploit":null}],"exploitCount":1,"weaknesses":[{"id":"CWE-347","name":"Improper Verification of Cryptographic Signature","description":"The product does not verify, or incorrectly verifies, the cryptographic signature for data.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/347.html"}],"affected":[{"vendor":"mikrotik","product":"routeros","name":"RouterOS","label":"routeros","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 7.0.0, < 7.23.6","noFixRecorded":false,"fixedIn":null},{"text":"≥ 7.0, < 7.23.6","noFixRecorded":false,"fixedIn":null},{"text":"≥ 7.24, < 7.24.3","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 7.0.0, < 7.23.6 | ≥ 7.0, < 7.23.6 | ≥ 7.24, < 7.24.3","eol":{"isEol":null,"eolDate":null,"matchMethod":"cpe","cycle":null,"product":{"name":"routeros","label":"RouterOS","category":"os"}},"hubHref":"/vendor/mikrotik/routeros"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve","label":"cert.pl/en/posts/2026/09/mikrotik-routeros-cve","hostname":"cert.pl","tags":["Third Party Advisory"]},{"url":"https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/","label":"cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/","hostname":"cert.pl","tags":["Technical Description","Mitigation","Third Party Advisory"]},{"url":"https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/","label":"npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/","hostname":"npratley.net","tags":["Exploit","Third Party Advisory"]},{"url":"https://mikrotik.com/supportsec/september-2026-vulnerability/","label":"mikrotik.com/supportsec/september-2026-vulnerability/","hostname":"mikrotik.com","tags":["Vendor Advisory"]},{"url":"https://forum.mikrotik.com/t/7-23-6-long-term-is-released/273139","label":"forum.mikrotik.com/t/7-23-6-long-term-is-released/273139","hostname":"forum.mikrotik.com","tags":["Release Notes"]},{"url":"https://forum.mikrotik.com/t/7-24-3-stable-is-released/273138","label":"forum.mikrotik.com/t/7-24-3-stable-is-released/273138","hostname":"forum.mikrotik.com","tags":["Release Notes"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-09-05T20:00:57.258Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-17T14:20:12.715Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":70,"level":"high","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T21:13:45.377Z","stale":false,"partial":false}}