MikroTik RouterOS <7.24 SMB OOB Read Vulnerability
CVE-2026-56719 Published on September 16, 2026
MikroTik RouterOS < 7.24 Out-of-Bounds Read via SMB1 SessionSetupAndX
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 Analysis
CVE-2026-56719 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
Out-of-bounds Read
The software reads data past the end, or before the beginning, of the intended buffer. Typically, this can allow attackers to read sensitive information from other memory locations or cause a crash. A crash can occur when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string. The expected sentinel might not be located in the out-of-bounds memory, causing excessive data to be read, leading to a segmentation fault or a buffer overflow. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent read operation then produces undefined or unexpected results.
Products Associated with CVE-2026-56719
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Affected Versions
MikroTik RouterOS:- Before and including 6.49.18 is affected.
- Version 7.0.0, <= 7.11.2 is affected.
- Version 7.24.0 is unaffected.