CVE-2026-3644 Details
The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().
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Exploit prediction scoring system (EPSS) score for CVE-2026-3644
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%).
0.39 Probability of exploitation activity being observed over the next 30 days (31th percentile)
CVSS score for CVE-2026-3644
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-2026-3644
Python 2.5
Python 2.5.1
Python 2.5.2
Python 2.5.4
Python 2.5.5
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-2026-3644 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 69,796 32.96%
DE 23,808 11.24%
CN 18,802 8.88%
KR 7,679 3.63%
BR 7,298 3.45%
SG 7,278 3.44%
NL 6,260 2.96%
JP 6,073 2.87%
GB 5,860 2.77%
FR 5,090 2.40%

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CVE-2026-3644 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 131,268 84.03%
Telecommunications 16,035 10.26%
Education 5,836 3.74%
Media/Entertainment 1,077 0.69%
Government/Politics 487 0.31%
Business Services 316 0.20%
Retail 271 0.17%
Energy/Resources 182 0.12%
Real Estate 155 0.10%
Utilities 108 0.07%

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