Out-of-bounds Read in Mikrotik Routeros

CVE-2026-56719

MikroTik RouterOS before 7.24 contains an out-of-bounds read vulnerability in the userspace SMB daemon that allows unauthenticated attackers to read beyond the end of the request buffer by supplying a crafted uniPwdLen field value in a minimal SMB1 SessionSetupAndX frame. The out-of-bounds read occurs in the SessionSetupAndX handler before any credential validation, potentially exposing sensitive memory contents.

Vulnerability class: Buffer Overflow

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-56719?
CVE-2026-56719 is a medium-severity vulnerability in Mikrotik Routeros, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-09-16.
How severe is CVE-2026-56719?
Medium severity. CVSS v3 base score is 6.5 out of 10.