Is CVE-2026-11503 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-11503 being exploited in the wild.

How severe is CVE-2026-11503?

High severity, with a CVSS score of 8.8, published 8 June 2026.

Is there a fix for CVE-2026-11503?

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-2026-11503 attacked?

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

Am I affected by CVE-2026-11503?

Check whether you run Tenda Cx12l 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-2026-11503: Tenda CX12L stack overflow in Wi-Fi Configuration Endpoint

CVE-2026-11503 · Severity: high · CVSS 8.8 · Published 2026-06-08

A security vulnerability exists in the Tenda CX12L router, a device used to provide Wi-Fi and networking for homes and small offices. An attacker can exploit this flaw to crash the router's management interface or potentially take full control of the device. This could lead to a total loss of internet connectivity or allow an unauthorized user to monitor network traffic and access sensitive data.

Technologies: Tenda Cx12l. Vendors: Tenda.

Quick answers

Is CVE-2026-11503 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-11503 being exploited in the wild.
How severe is CVE-2026-11503?: High severity, with a CVSS score of 8.8, published 8 June 2026.
Which products and versions are affected?: Tenda Cx12l 16.03.53.12.
Is there a fix for CVE-2026-11503?: 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-2026-11503 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-11503?: Check whether you run Tenda Cx12l 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

A stack-based buffer overflow vulnerability exists in the 'form_fast_setting_wifi_set' function within the '/goform/fast_setting_wifi_set' endpoint of Tenda CX12L firmware (v16.03.53.12). The root cause is the unsafe use of the 'sprintf' function when processing the user-controlled 'ssid' parameter. Specifically, when the device generates a 5GHz SSID, it appends '_5G' to the input and copies it into a fixed 64-byte stack buffer without length validation. An attacker with network access and low-level privileges can provide an overly long SSID string to overwrite the stack, including the saved frame pointer and return address, enabling arbitrary code execution or a crash of the 'httpd' process. A public exploit has been disclosed.

Affected products

Tenda CX12L 16.03.53.12

Timeline

2026-05-22: disclosed: Vulnerability details and PoC published on GitHub
2026-06-08: advisory: CVE-2026-11503 published

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.