CVE-2026-67277 - Kernel memory disclosure and denial of service in MikroTik RouterOS btest service
Brief
CVE ID : CVE-2026-67277
Published : Sept. 5, 2026, 8:17 p. m.
- 28 minutes ago
Description : 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.
This issue was fixed in versions: 6.
- 21 (Lont-term), 7.
- 4 (Lont-term) and 7.
- 2 (Stable)
Severity: 8.8
- HIGH