High severity · published Sep 29, 2025
CVE-2025-9648
Denial of Service in CivetWeb
8.7
CVSS
0.8%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 55% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CI
CivetWeb · CivetWeb
1.10 through 1.16 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-9648
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-9648
cert.pl
https://cert.pl/en/posts/2025/09/CVE-2025-9648
github.com
https://github.com/civetweb/civetweb
github.com
https://github.com/civetweb/civetweb/commit/782e18903515f43bafbf2e668994e82bdfa51133
github.com
https://github.com/civetweb/civetweb/issues/1348
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