Stack-Based Buffer Overflow Vulnerability in Belkin F9K1122 Router
CVE-2026-5042

8.7HIGH

Key Information:

Vendor

Belkin

Status
F9k1122
Vendor
CVE Published:
29 March 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-5042?

A security flaw has been identified in the Belkin F9K1122 router, specifically in the function formCrossBandSwitch located within the Parameter Handler component. The vulnerability allows for a stack-based buffer overflow, triggered by manipulation of the argument in the webpage parameter. This vulnerability can be exploited remotely, posing a significant risk as the exploit code has been publicly released. Initial notification to the vendor about this issue went unanswered, highlighting a potential gap in their security response.

Affected Version(s)

F9K1122 1.00.33

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-5042 - Proof of Concept

References

https://vuldb.com/vuln/353965
vdb-entrytechnical-description
https://vuldb.com/vuln/353965/cti
signaturepermissions-required
https://vuldb.com/submit/779123
third-party-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

LtzHuster2 (VulDB User)
VulDB
.