CVE-2026-78050: Comfast CF-N1-S stack buffer overflow in NTP timezone configuration

CVE-2026-78050 · Severity: critical · CVSS 9.9 · Published 2026-08-23

Comfast CF-N1-S is a WiFi router with a web-based management interface. A stack buffer overflow vulnerability in the NTP timezone settings allows a remote attacker with network access to send a malicious HTTP request and execute arbitrary code on the device, potentially compromising all traffic routed through it or enabling lateral movement into the network.

Technologies: Comfast CF-N1-S. Vendors: Comfast.

Quick answers

Is CVE-2026-78050 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-78050 being exploited in the wild.
How severe is CVE-2026-78050?
Critical severity, with a CVSS score of 9.9, published 23 August 2026.
Which products and versions are affected?
Comfast CF-N1-S 2.6.0.1.
Is there a fix for CVE-2026-78050?
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-2026-78050 attacked?
It is attacked over the network, in device firmware.
Am I affected by CVE-2026-78050?
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_41AD7C function of the web management endpoint /cgi-bin/mbox-config?method=SET&section=ntp_timezone. The function accepts a 'timestr' parameter via JSON POST body and passes it unsanitized to sprintf(), which concatenates it with the format string "date -s \"%s\" > /dev/null" before writing to a fixed-size stack buffer. No bounds checking occurs, allowing an attacker to overwrite the return address with a long timestr value. The attack requires network reachability to the router's web interface (typically requires a valid session or unauthenticated access depending on configuration). Proof-of-concept code has been publicly disclosed, and exploit code is available.

Affected products

  • Comfast CF-N1-S 2.6.0.1

Timeline

  • 2026-07-06: disclosed: Vulnerability report published on GitHub
  • 2026-08-23: advisory: CVE-2026-78050 published

References

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