Excessive Iteration in Tornado - CVE-2025-67726
Published: December 12, 2025
Vulnerability identifier: #VU119883
CSH Severity: Medium
CVSS v4.0: 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/E:U/U:Green
CVE-ID: CVE-2025-67726
CWE-ID: CWE-834
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Tornado
Affected software:
Tornado
Tornado
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to excessive iteration within the _parseparam() function in httputil.py when parsing specific HTTP header values. A remote attacker can send a specially crafted HTTP request and perform a denial of service attack
How to mitigate CVE-2025-67726
Install updates from vendor's website.