CVE-2026-125406 Ettercap through 0.8.4.1 Stack Buffer Underwrite via Telnet Dissector Backspace Handling

High 8.7 Published 9 Nov 2026 Updated 9 Nov 2026

Exploited in the wild: Not known
Fix: None listed

What is CVE-2026-125406?

CVE-2026-125406 is a high-severity vulnerability in ettercap, published on 9 Nov 2026.

Official description

Ettercap through 0.8.4.1 contains a stack buffer underwrite vulnerability in the telnet dissector in src/dissectors/ec_telnet.c that decrements the output pointer on backspace without a lower bound check. Attackers can send a telnet stream with more backspaces than preceding characters to write below the stack buffer, corrupting the stack of the Ettercap process that normally runs as root.

Weakness: CWE-124

Which versions are affected by CVE-2026-125406?

How do I fix CVE-2026-125406?

No fix has been published for CVE-2026-125406 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-125406 being exploited?

There is no known exploitation of CVE-2026-125406 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2026-125406, GHSA-cq94-w9q3-ggxw, GHSA-w5ch-7c4x-crcc, UBUNTU-CVE-2026-125406.