Stack-based Buffer Overflow in Wavlink WL-NU516U1-A wireless.cgi Guest_ssid Handler
CVE-2026-13539 is a remotely exploitable stack-based buffer overflow in Wavlink WL-NU516U1-A firmware M16U1_V240425. The flaw is in the POST parameter handling logic of /cgi-bin/wireless.cgi, specifically in function sub_407504. An attacker can trigger the vulnerability by supplying a crafted value for the Guest_ssid argument, causing unsafe copying or handling of attacker-controlled input into a stack buffer. Successful exploitation may corrupt stack memory and can lead to process crash or potentially arbitrary code execution, depending on exploitability conditions on the target device. Public exploit code is reported to be available.
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Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Recent activity
8 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.