Stack-based buffer overflow in CivetWeb - CVE-2025-55763
Published: September 3, 2025 / Updated: November 24, 2025
Vulnerability identifier: #VU114768
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-55763
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when handling HTTP requests. A remote unauthenticated attacker can send a specially crafted HTTP request, trigger a stack-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Affected software
CivetWeb
Fedora
Ubuntu
civetweb (Ubuntu package)
civetweb
Fedora
Ubuntu
civetweb (Ubuntu package)
civetweb
How to mitigate CVE-2025-55763
Install update from vendor's website.
civetweb (Ubuntu package) - addressed in versions 1.15+dfsg-3ubuntu0.1~esm1, 1.16+dfsg-1ubuntu0.1, 1.16+dfsg-3ubuntu0.1
civetweb - addressed in versions 1.16-9.el8, 1.16-9.el9, 1.16-9.el10_2, 1.16-9.fc41, 1.16-9.fc42, 1.16-9.fc43
civetweb - addressed in versions 1.16-9.el8, 1.16-9.el9, 1.16-9.el10_2, 1.16-9.fc41, 1.16-9.fc42, 1.16-9.fc43