CVE-2025-9648

Description

A vulnerability in the CivetWeb library's function mg_handle_form_request allows remote attackers to trigger a denial of service (DoS) condition. By sending a specially crafted HTTP POST request containing a null byte in the payload, the server enters an infinite loop during form data parsing. Multiple malicious requests will result in complete CPU exhaustion and render the service unresponsive to further requests. This issue was fixed in commit 782e189. This issue affects only the library, standalone executable pre-built by vendor is not affected.

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Weakness Type (CWE)

CWE-158 CWE-158

References

Other References

https://cert.pl/en/posts/2025/09/CVE-2025-9648 https://github.com/civetweb/civetweb https://github.com/civetweb/civetweb/commit/782e18903515f43bafbf2e668994e82bdfa51133 https://github.com/civetweb/civetweb/issues/1348

Frequently Asked Questions

What is CVE-2025-9648? +

A vulnerability in the CivetWeb library's function mg_handle_form_request allows remote attackers to trigger a denial of service (DoS) condition. By sending a specially crafted HTTP POST request containing a null byte in the payload, the server enters an infinite loop during form data parsing. Multiple malicious requests will result in complete CPU exhaustion and render the service unresponsive to further requests. This issue was fixed in commit 782e189. This issue affects only the library, standalone executable pre-built by vendor is not affected.

How do I check if I'm vulnerable to CVE-2025-9648? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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