{"id":"CVE-2026-67277","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-67277","summary":"RouterOS accepts a \"related\" btest connection before the corresponding primary session has completed authentication. An unauthenticated client can use this state to start an IPv4 UDP…","details":"RouterOS accepts a \"related\" btest connection before the corresponding primary session has completed authentication. An unauthenticated client can use this state to start an IPv4 UDP test. With \"random-data=false\", the sender transmits an uninitialized tail from a kernel packet buffer. A separate unchecked, inverted packet-size interval causes unsigned integer underflow, anomalously large fragmented output, and can restart the RouterOS kernel.\n\n\n\nThis issue was fixed in versions: 6.49.21 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable)","published":"2026-09-05T20:17:18.120","modified":"2026-09-05T20:17:18.120","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":null,"references":[{"type":"WEB","url":"https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve"},{"type":"WEB","url":"https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/"},{"type":"WEB","url":"https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802"},{"type":"WEB","url":"https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801"},{"type":"WEB","url":"https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800"},{"type":"WEB","url":"https://mikrotik.com/supportsec/september-2026-vulnerability/"},{"type":"WEB","url":"https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-09-05T20:17:18.120"}}