CVE-2026-56719 MikroTik RouterOS < 7.24 Out-of-Bounds Read via SMB1 SessionSetupAndX
Unauthenticated attackers can read sensitive memory contents via a crafted SMB1 packet in MikroTik RouterOS, requiring an upgrade to mitigate.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56719?
CVE-2026-56719 is a medium-severity vulnerability in MikroTik RouterOS, published on 16 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-125
Which versions are affected by CVE-2026-56719?
How do I fix CVE-2026-56719?
No fix has been published for CVE-2026-56719 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-56719 being exploited?
There is no known exploitation of CVE-2026-56719 in the wild and no public exploit code.
Sources
Also known as GHSA-w9p3-2qvw-6779.