Vulnerability record
CVE-2026-125406
The short answer
CVE-2026-125406 affects Ettercap ettercap and is rated high (CVSS 8.7). It is not in CISA's KEV catalog; EPSS puts the chance of exploitation in the next 30 days at 0.24%.
What it is
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.
Severity
8.7 high
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Exploited (CISA KEV)
Not listed
CISA lists confirmed exploitation only
EPSS, next 30 days
0.24%
Higher than 15% of scored CVEs
How it can be exploited
- Attack vector
- Adjacent network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Affected products
ettercap. NVD's record lists the exact affected versions.
References
- github.com/Ettercap/ettercap/blob/v0.8.4.1/src/dissectors/ec_telnet.c#L150-L159
- github.com/Ettercap/ettercap/commit/1d8badb713579419a29a494bb463a1af59707e98
- github.com/Ettercap/ettercap/pull/1330
- github.com/Ettercap/ettercap/security/advisories/GHSA-w5ch-7c4x-crcc
- www.vulncheck.com/advisories/ettercap-through-0.8.4.1-stack-buffer-underwrite-via-telnet-dissector-backspace-handling
Questions
Is CVE-2026-125406 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog as of 2026-11-11. FIRST's EPSS estimates a 0.24% chance of exploitation in the next 30 days.
How do I fix CVE-2026-125406?
Follow the vendor advisory in the references below. NVD lists the affected versions under its configurations.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Received. The description is NVD's text, quoted as published.
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