CVE-2026-5629
Published: 06 April 2026
Summary
CVE-2026-5629 is a high-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Belkin F9K1015 Firmware. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 28.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly validates the 'webpage' argument input to the formSetFirewall function, preventing the stack-based buffer overflow exploitation.
Implements memory protections such as stack canaries, ASLR, and non-executable stacks to mitigate stack-based buffer overflow vulnerabilities like this one.
Requires timely identification, reporting, and remediation of flaws like this buffer overflow through patching or replacement, reducing exploitation risk.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The stack-based buffer overflow in the router's public web interface (/goform/formSetFirewall) directly enables remote exploitation of a public-facing application (T1190) with low privileges, resulting in arbitrary code execution and full device compromise, which constitutes exploitation for privilege escalation (T1068).
NVD Description
A vulnerability was detected in Belkin F9K1015 1.00.10. The affected element is the function formSetFirewall of the file /goform/formSetFirewall. The manipulation of the argument webpage results in stack-based buffer overflow. The attack can be executed remotely. The exploit is now…
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public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Deeper analysisAI
CVE-2026-5629 is a stack-based buffer overflow vulnerability in the Belkin F9K1015 router running firmware version 1.00.10. The issue resides in the formSetFirewall function within the /goform/formSetFirewall file, where manipulation of the "webpage" argument triggers the overflow. This flaw, classified under CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) and CWE-121 (Stack-based Buffer Overflow), carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.
The vulnerability can be exploited remotely by an attacker with low privileges (PR:L), requiring low attack complexity and no user interaction. Successful exploitation allows arbitrary code execution, granting high levels of confidentiality, integrity, and availability impact, potentially leading to full device compromise such as unauthorized access, data theft, or further network pivoting from the affected router.
VulDB advisories and the associated GitHub repository document the issue, noting that a public exploit is available and that the vendor was contacted early but provided no response or patch. No official mitigation or firmware update is referenced, leaving affected devices reliant on network segmentation, access controls, or device replacement to reduce exposure.
The exploit's public availability increases the risk of widespread abuse, though no specific real-world exploitation in the wild is detailed beyond the disclosure.
Details
- CWE(s)