Authenticated code execution via serverString overflow
Published Feb 22, 2026 · Updated Feb 22, 2026
Stack-based buffer overflow in Tenda HG9 300001138 allows remote authenticated users to execute code or crash the web service. The formSamba function passes the request-controlled serverString value to sprintf, which writes a shell command into the 64-byte stack buffer v14 without a length bound. Reachability requires management access and sambaCap set to 1; overflowing v14 corrupts control data, enabling code execution or an HTTP-service crash.
Summary
What happened
Stack-based buffer overflow in Tenda HG9 300001138 allows remote authenticated users to execute code or crash the web service. The formSamba function passes the request-controlled serverString value to sprintf, which writes a shell command into the 64-byte stack buffer v14 without a length bound. Reachability requires management access and sambaCap set to 1; overflowing v14 corrupts control data, enabling code execution or an HTTP-service crash.
The record
- CVE
- CVE-2026-2906
- Published
- Feb 22, 2026
- Updated
- Feb 22, 2026
- Vendor
- Shenzhen Tenda Technology Co., Ltd.
- Product
- HG9
- Classifications
- CWE-121, CWE-119, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 22, 2026CVE publishedPublication date reported by the CVE source.
- Feb 22, 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?
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- Affected versionversion=300001138
What conditions does exploitation require?
What is affected?
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
- Tenda HG9 formSamba serverString overflow proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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