Authenticated denial of service via unchecked if copy
Published Sep 6, 2026 · Updated Sep 6, 2026
Buffer overflow in the Boa Web Server on Tenda HG10 300001138 allows remote authenticated users to crash the router via an overlong if parameter. The formWanRedirect handler reads if with boaGetVar and passes it to strcpy for a fixed-size buffer without validating the input length, overwriting adjacent memory. Low-privileged access to the web management interface is required; the demonstrated request leaves the router unresponsive.
Summary
What happened
Buffer overflow in the Boa Web Server on Tenda HG10 300001138 allows remote authenticated users to crash the router via an overlong if parameter. The formWanRedirect handler reads if with boaGetVar and passes it to strcpy for a fixed-size buffer without validating the input length, overwriting adjacent memory. Low-privileged access to the web management interface is required; the demonstrated request leaves the router unresponsive.
The record
- CVE
- CVE-2026-86166
- Published
- Sep 6, 2026
- Updated
- Sep 6, 2026
- Vendor
- Shenzhen Tenda Technology Co., Ltd.
- Product
- HG10
- Classifications
- CWE-119, CWE-120, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 6, 2026CVE publishedPublication date reported by the CVE source.
- Sep 6, 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?
Published CVSS scores
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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
- formWanRedirect if buffer-overflow proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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