Authenticated code execution via password escaping overflow
Published Feb 16, 2026 · Updated Feb 16, 2026
Stack buffer overflow in Wavlink WL-NU516U1 firmware 20251208 allows remote authenticated users to hijack execution via User1Passwd. In sub_4051B0, each password character is prefixed with a backslash and appended by strcat to a 128-byte stack buffer without bounds checks. A valid session cookie and enable_storage_management=1 are required; the published request demonstrates a CGI crash, while return-address overwrite permits execution-flow hijacking.
Summary
What happened
Stack buffer overflow in Wavlink WL-NU516U1 firmware 20251208 allows remote authenticated users to hijack execution via User1Passwd. In sub_4051B0, each password character is prefixed with a backslash and appended by strcat to a 128-byte stack buffer without bounds checks. A valid session cookie and enable_storage_management=1 are required; the published request demonstrates a CGI crash, while return-address overwrite permits execution-flow hijacking.
The record
- CVE
- CVE-2026-2567
- Published
- Feb 16, 2026
- Updated
- Feb 16, 2026
- Vendor
- Wavlink
- Product
- WL-NU516U1
- Classifications
- CWE-119, CWE-121, CWE-787, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 16, 2026CVE publishedPublication date reported by the CVE source.
- Feb 16, 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=20251208
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
- Wavlink NU516U1 nas.cgi User1Passwd proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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