# CVE-2026-77148: Comfast CF-N1-S stack-based buffer overflow in web management

Source: https://junglewise.ai/threats/cve-2026-77148-comfast-cf-n1-s-stack-based-buffer-overflow-in-web-management  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77148 · Severity: critical · CVSS 9.9 · Published 2026-08-20

Comfast CF-N1-S is a wireless router used to provide network connectivity. A stack-based buffer overflow vulnerability in its web management interface allows a remote attacker to craft a malicious HTTP request that overwrites critical stack memory, potentially leading to arbitrary code execution and complete compromise of the device.

Technologies: [Comfast CF-N1-S](https://junglewise.ai/threats/technologies/cf-n1-s). Vendors: [Comfast](https://junglewise.ai/threats/vendors/comfast).

## Quick answers

**Is CVE-2026-77148 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77148 being exploited in the wild.

**How severe is CVE-2026-77148?** Critical severity, with a CVSS score of 9.9, published 20 August 2026.

**Which products and versions are affected?** Comfast CF-N1-S 2.6.0.1.

**Is there a fix for CVE-2026-77148?** 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-2026-77148 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-77148?** Check whether you run Comfast CF-N1-S 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 a stack-based buffer overflow in the sub_44B50C function within the /cgi-bin/mbox-config endpoint. The function uses a sprintf-like operation (off_47D1FC) to concatenate user-supplied input (the "channel" parameter) with the format string "ptest setchannel %s" into a 64-byte stack buffer without validating the input length or performing boundary checks. When an attacker sends a specially crafted HTTP POST request with an oversized channel value to the endpoint /?method=SET&section=ptest_channel, the buffer overflows and corrupts the return address and other critical stack data. The attack requires network reachability to the router's web management interface but does not require prior authentication. Exploitation can lead to arbitrary code execution with the privileges of the web server process.

## Affected products

- Comfast CF-N1-S 2.6.0.1

## Timeline

- 2026-07-06: disclosed: Vulnerability disclosed on GitHub
- 2026-08-20: advisory: CVE-2026-77148 published

## References

- [https://github.com/AdminSafe/CVE/issues/7](https://github.com/AdminSafe/CVE/issues/7)
- [https://vuldb.com/cve/CVE-2026-77148](https://vuldb.com/cve/CVE-2026-77148)

## Related threats

- [Comfast CF-N1-S stack-based buffer overflow in web management](https://junglewise.ai/threats/cve-2026-94003-a-vulnerability-has-been-found-in-comfast-cf-n1-s-2-6-0-1)
- [Comfast CF-N1-S command injection in webmgnt](https://junglewise.ai/threats/cve-2026-75364-comfast-cf-n1-s-command-injection-in-webmgnt)
- [Comfast CF-N1-S stack buffer overflow in NTP timezone configuration](https://junglewise.ai/threats/cve-2026-78050-comfast-cf-n1-s-stack-buffer-overflow-in-ntp-timezone)
- [Comfast CF-N1-S command injection in NTP timezone](https://junglewise.ai/threats/cve-2026-77683-comfast-cf-n1-s-command-injection-in-ntp-timezone)
- [Comfast CF-N1-S stack-based buffer overflow in SSID configuration](https://junglewise.ai/threats/cve-2026-77022-comfast-cf-n1-s-stack-based-buffer-overflow-in-ssid-configuration)