CVE-2026-9659: Stack Overflow (CVSS 9.1)

Description

Multiple exploitable stack-based buffer overflow vulnerabilities exist in the boa formFilter functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger these vulnerabilities. This vulnerability deals with the vpnUser parameter.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0079

Probability of exploitation

0.56%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-121 CWE-121

References

Other References

https://talosintelligence.com/vulnerability_reports/TALOS-2026-2425

Frequently Asked Questions

What is CVE-2026-9659? +

Multiple exploitable stack-based buffer overflow vulnerabilities exist in the boa formFilter functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger these vulnerabilities. This vulnerability deals with the vpnUser parameter. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-9659? +

CVE-2026-9659 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0079, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-9659? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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