Is CVE-2026-123966 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-123966 being exploited in the wild.

How severe is CVE-2026-123966?

Critical severity, with a CVSS score of 10, published 7 November 2026.

Is there a fix for CVE-2026-123966?

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-2026-123966 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-123966?

Check whether you run Tenda AC19 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.

CVE-2026-123966: Tenda AC19 heap buffer overflow in saveParentControlInfo

CVE-2026-123966 · Severity: critical · CVSS 10 · Published 2026-11-07

The Tenda AC19 Wi-Fi router's web management interface contains a heap buffer overflow vulnerability in the saveParentControlInfo function that can be exploited remotely without authentication. An attacker can send a specially crafted request to crash the router's web service, force a reboot, or potentially execute arbitrary code with root privileges. This affects any AC19 device exposed to network access, putting both the device and connected networks at risk.

Vendors: Tenda.

Quick answers

Is CVE-2026-123966 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-123966 being exploited in the wild.
How severe is CVE-2026-123966?: Critical severity, with a CVSS score of 10, published 7 November 2026.
Which products and versions are affected?: Tenda AC19 16.03.10.07.
Is there a fix for CVE-2026-123966?: 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-2026-123966 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-123966?: Check whether you run Tenda AC19 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 heap-based buffer overflow (CWE-122) in the /goform/saveParentControlInfo endpoint, where user-controlled parameters (deviceId, time, and urls) are copied into fixed-size buffers using unsafe functions like strcpy() without length validation. The deviceId parameter is written to a 596-byte heap buffer via strcpy(ptr + 2, src), and the time parameter is parsed into 4-byte stack buffers via unbounded sscanf() conversions. No authentication is required, making this remotely exploitable by any attacker with network access to the device.

Affected products

Tenda AC19 16.03.10.07

Timeline

2026-11-07: disclosed

References

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