Is CVE-2026-9817 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-9817 being exploited in the wild.

How severe is CVE-2026-9817?

Critical severity, with a CVSS score of 9.1, published 20 October 2026.

Which products and versions are affected?

TOTOLINK X2000r TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327.

Is there a fix for CVE-2026-9817?

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-2026-9817 attacked?

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

Am I affected by CVE-2026-9817?

Check whether you run TOTOLINK X2000r 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-2026-9817: Totolink X2000R stack-based buffer overflow in boa formUploadFile

CVE-2026-9817 · Severity: critical · CVSS 9.1 · Published 2026-10-20

The Totolink X2000R is a home router that manages network configuration through a web interface. A stack-based buffer overflow vulnerability in the file upload functionality allows an authenticated attacker to execute arbitrary code on the router by sending a specially crafted HTTP request with an oversized filename. This could give an attacker complete control over the router and access to all connected devices and network traffic.

Technologies: TOTOLINK X2000r. Vendors: TOTOLINK.

Quick answers

Is CVE-2026-9817 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-9817 being exploited in the wild.
How severe is CVE-2026-9817?: Critical severity, with a CVSS score of 9.1, published 20 October 2026.
Which products and versions are affected?: TOTOLINK X2000r TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327.
Is there a fix for CVE-2026-9817?: 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-2026-9817 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-9817?: Check whether you run TOTOLINK X2000r 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 (CWE-121) exists in the formUploadFile() function of the boa web server binary when processing multipart form data uploads. The vulnerability occurs at line [4] where a filename extracted from the HTTP request is copied into a fixed-size stack buffer (0xc8 bytes) without length validation using sprintf(). An authenticated attacker can exploit this via a crafted HTTP POST request to the /boafrm/formUploadFile endpoint with a malicious filename in the multipart data, resulting in stack corruption and arbitrary code execution.

Affected products

Totolink X2000R TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327

Timeline

2026-10-20: disclosed
2026-10-20: advisory

References

https://talosintelligence.com/vulnerability_reports/TALOS-2026-2429

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