CVE-2025-67726 Details
Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server's CPU usage increases quadratically (O(n²)) during parsing. Due to Tornado's single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3.
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Exploit prediction scoring system (EPSS) score for CVE-2025-67726
EPSS (Exploit Prediction Scoring System): EPSS predicts the likelihood that a vulnerability will be exploited in the wild. A higher percentage means a greater chance of an exploit occurring. The EPSS model produces a probability score between 0 and 1 (0 and 100%).
0.08 Probability of exploitation activity being observed over the next 30 days (23rd percentile)
CVSS score for CVE-2025-67726
CVSS (Common Vulnerability Scoring System): An open framework owned and managed by FIRST.Org, Inc. that assigns a numerical score from 0 to 10 to software vulnerabilities to indicate their severity.
7.5 High
Products affected by CVE-2025-67726
Tornado 4.5.2
Tornado 4.5.3
Tornado 5.0.1
Tornado 5.0.2
Tornado 5.1.1
DVE Score by Bitsight AI
DVE scores complement traditional static scoring systems like CVSS with Bitsight AI powered real-time threat intelligence and underground cyber criminal activity so that security teams can reduce alert fatigue and focus on vulnerabilities most likely to be exploited.
Low
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CVE-2025-67726 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 669 43.47%
CN 162 10.53%
DE 112 7.28%
GB 47 3.05%
KR 45 2.92%
JP 45 2.92%
SG 44 2.86%
FR 44 2.86%
IE 35 2.27%
IN 33 2.14%

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CVE-2025-67726 Industry Footprint

Top 10 Identified Industries

*Service provider organizations (typically Technology and Telecommunications) are disproportionally represented in the results given their upstream ownership of end-user infrastructure. See our FAQs.

Industry* Observations Percentage
Technology 1,044 84.47%
Telecommunications 127 10.28%
Education 42 3.40%
Government/Politics 6 0.49%
Business Services 4 0.32%
Media/Entertainment 3 0.24%
Retail 3 0.24%
Healthcare/Wellness 2 0.16%
Energy/Resources 1 0.08%
Consumer Goods 1 0.08%

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