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.
References (4)
Core 4
Core References
Various Sources third-party-advisory
https://cert.pl/en/posts/2025/09/CVE-2025-9648
Various Sources product
https://github.com/civetweb/civetweb
Issue Tracking issue-tracking
https://github.com/civetweb/civetweb/issues/1348
Scores
CVSS v4
8.7
EPSS
0.0089
EPSS Percentile
75.7%
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-158
Status
published
Products (3)
CivetWeb/CivetWeb
< 1.08
CivetWeb/CivetWeb
1.08 - 1.10
CivetWeb/CivetWeb
1.10 - 1.16
Published
Sep 29, 2025
Tracked Since
Feb 18, 2026