Authenticated code execution via unchecked webpage copy
Published Mar 29, 2026 · Updated Mar 29, 2026
Stack-based buffer overflow in Belkin F9K1122 1.00.33 allows remote authenticated users to crash the extender or execute code. The formCrossBandSwitch handler passes data derived from the webpage parameter to strcpy without checking its length, overflowing the stack-based reboot_msg buffer. Access to authenticated web management is required; a crafted POST can interrupt service or run code with the web process's privileges.
Summary
What happened
Stack-based buffer overflow in Belkin F9K1122 1.00.33 allows remote authenticated users to crash the extender or execute code. The formCrossBandSwitch handler passes data derived from the webpage parameter to strcpy without checking its length, overflowing the stack-based reboot_msg buffer. Access to authenticated web management is required; a crafted POST can interrupt service or run code with the web process's privileges.
The record
- CVE
- CVE-2026-5042
- Published
- Mar 29, 2026
- Updated
- Mar 29, 2026
- Vendor
- Belkin
- Product
- N600 Dual-Band Plug-in Wi‑Fi Range Extender
- Classifications
- CWE-787, CWE-121, CWE-119, T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 29, 2026CVE publishedPublication date reported by the CVE source.
- Mar 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.00.33
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- F9K1122 formCrossBandSwitch overlong webpage POSTproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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