Unauthenticated code execution via cookie overflow
Published Aug 17, 2026 · Updated Aug 17, 2026
Stack-based buffer overflow in Wavlink WN531P3 and WN535M1 V250922 allows remote attackers to execute code via HTTP_COOKIE. In /etc/lighttpd/www/cgi-bin/export_pingortrace.cgi, the Export Pingortrace CGI reads the Cookie header with getenv("HTTP_COOKIE") and copies it into a fixed 256-byte stack buffer with strcpy before token validation. Unauthenticated network access to the CGI is sufficient; an oversized Cookie value can overwrite saved MIPS registers and the return address, and the published proof of concept demonstrates ret2libc-style command execution.
Summary
What happened
Stack-based buffer overflow in Wavlink WN531P3 and WN535M1 V250922 allows remote attackers to execute code via HTTP_COOKIE. In /etc/lighttpd/www/cgi-bin/export_pingortrace.cgi, the Export Pingortrace CGI reads the Cookie header with getenv("HTTP_COOKIE") and copies it into a fixed 256-byte stack buffer with strcpy before token validation. Unauthenticated network access to the CGI is sufficient; an oversized Cookie value can overwrite saved MIPS registers and the return address, and the published proof of concept demonstrates ret2libc-style command execution.
The record
- CVE
- CVE-2026-74843
- Published
- Aug 17, 2026
- Updated
- Aug 17, 2026
- Vendor
- Wavlink
- Product
- WN531P3
- Classifications
- CWE-119, CWE-121, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 17, 2026CVE publishedPublication date reported by the CVE source.
- Aug 17, 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=V250922
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
- CVE-Report-WAVLINK-WN535M1-RCE.pdffunctional · demonstrated
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Technologies
Your stack
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Your stack
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