CVE-2026-125406 json
Ettercap through 0.8.4.1 Stack Buffer Underwrite via Telnet Dissector Backspace Handling
published 6d ago modified yesterday also EUVD-2026-120569 , GHSA-w5ch-7c4x-crcc
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository Ettercap/ettercap. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 15%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- github.com/Ettercap/ettercap@1d8badb commit
- github.com/Ettercap/ettercap#1330 pull request
Is CVE-2026-125406 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerExploit prediction
0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-11).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | 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 |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.7 | 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 |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- Ettercap ettercap
Classification
- Weakness
-
- CWE-124 Buffer Underwrite
References
-
github.com
/Ettercap/ettercap/commit/1d8badb713579419a29a494bb463a1af59707e98
patch
-
github.com
/Ettercap/ettercap/pull/1330
issue-tracking, patch
-
github.com
/Ettercap/ettercap/security/advisories/GHSA-w5ch-7c4x-crcc
vendor-advisory, advisory
-
github.com
/Ettercap/ettercap/blob/v0.8.4.1/src/dissectors/ec_telnet.c#L150-L159
technical-description
-
vulncheck.com
/advisories/ettercap-through-0.8.4.1-stack-buffer-underwrite-via-telnet-dissector-backspace-handling
third-party-advisory
Sources
- CVE List CVE-2026-125406
- NVD CVE-2026-125406
- Maintainer advisory GHSA-w5ch-7c4x-crcc
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of Ettercap/ettercap published their own advisory on GitHub. Reviewed sources take precedence over it.