CVE-2026-67277

Name of the Vulnerable Software and Affected Versions RouterOS versions prior to 6.49.21 RouterOS versions prior to 7.23.4 RouterOS versions prior to 7.24.2

Description An unauthenticated client can initiate an IPv4 UDP test by exploiting a state where the system accepts a related btest connection before the primary session authentication is complete. When the random-data variable is set to false, the sender transmits an uninitialized tail from a kernel packet buffer. Additionally, an unchecked, inverted packet-size interval leads to an unsigned integer underflow, resulting in anomalously large fragmented output and a potential restart of the RouterOS kernel.

Recommendations Update to version 6.49.21 (Long-term). Update to version 7.23.4 (Long-term). Update to version 7.24.2 (Stable).