# CVE-2026-125403: Ettercap out-of-bounds read in SSL header stripping

Source: https://junglewise.ai/threats/cve-2026-125403-ettercap-through-0-8-4-1-contains-an-out-of-bounds-read-and-size  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-125403 · Severity: high · CVSS 8.1 · Published 2026-11-10

Ettercap is a network traffic interception and analysis tool that processes HTTPS traffic by intercepting SSL connections. A malicious HTTPS server can crash Ettercap or corrupt its memory by sending a specially crafted response, potentially leading to code execution since Ettercap typically runs with root privileges.

Technologies: [Ettercap](https://junglewise.ai/threats/technologies/ettercap-ettercap). Vendors: [Ettercap](https://junglewise.ai/threats/vendors/ettercap).

## Quick answers

**Is CVE-2026-125403 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-125403 being exploited in the wild.

**How severe is CVE-2026-125403?** High severity, with a CVSS score of 8.1, published 10 November 2026.

**Which products and versions are affected?** Ettercap through 0.8.4.1.

**Is there a fix for CVE-2026-125403?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-125403 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-125403?** Check whether you run Ettercap at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an out-of-bounds read and size_t underflow in the sslw_remove_sts() function in src/ec_sslwrap.c, triggered when stripping Strict-Transport-Security headers from intercepted HTTPS responses. The flaw results from a stale length value and an unchecked memmem() result that fails to validate the header's presence before attempting to remove it, allowing memory corruption when processing a malicious server response.

## Affected products

- Ettercap Ettercap through 0.8.4.1

## Timeline

- 2026-11-10: disclosed

## References

- [https://github.com/Ettercap/ettercap/blob/v0.8.4.1/src/ec_sslwrap.c](https://github.com/Ettercap/ettercap/blob/v0.8.4.1/src/ec_sslwrap.c)
- [https://github.com/Ettercap/ettercap/commit/1d8badb713579419a29a494bb463a1af59707e98](https://github.com/Ettercap/ettercap/commit/1d8badb713579419a29a494bb463a1af59707e98)

## Related threats

- [Ettercap stack buffer underwrite in telnet dissector](https://junglewise.ai/threats/cve-2026-125406-ettercap-through-0-8-4-1-contains-a-stack-buffer-underwrite)
- [Ettercap out-of-bounds read in NTLM parsing](https://junglewise.ai/threats/cve-2026-125405-ettercap-through-0-8-4-1-contains-an-out-of-bounds-read)
- [Ettercap integer underflow in CCMP decryption](https://junglewise.ai/threats/cve-2026-125404-ettercap-through-0-8-4-1-contains-an-integer-underflow-in-ccmp)
- [Ettercap heap buffer overflow in Gadu-Gadu dissector](https://junglewise.ai/threats/cve-2026-125401-ettercap-through-0-8-4-1-contains-a-heap-buffer-overflow)
- [Ettercap use-after-free in PCRE filter processing](https://junglewise.ai/threats/cve-2026-125400-ettercap-through-0-8-4-1-contains-a-use-after-free-vulnerability)