CVE-2026-55276 Details
Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat meant that special roles and empty authorisation constraints were not included when the effective web.xml was logged.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.0.M1 through 9.0.118, from 8.5.0 through 8.5.100. Other versions that have reached end of support may also be affected.

Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119 which fixes the issue.
View at NVD
Exploit prediction scoring system (EPSS) score for CVE-2026-55276
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%).
0.37 Probability of exploitation activity being observed over the next 30 days (29th percentile)
CVSS score for CVE-2026-55276
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.
9.1 Critical
Products affected by CVE-2026-55276
Tomcat 5.5.6
Tomcat 5.5.7
Tomcat 5.5.8
Tomcat 5.5.9
Tomcat 6.0.0
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-2026-55276 Global Footprint

Top 10 Identified Countries

Country Observations Percentage
US 12,695 24.77%
CN 11,600 22.64%
KR 2,779 5.42%
DE 2,416 4.71%
IN 2,316 4.52%
BR 1,628 3.18%
SG 1,491 2.91%
JP 1,207 2.36%
FR 1,114 2.17%
HK 1,007 1.97%

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CVE-2026-55276 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 29,496 77.62%
Telecommunications 5,688 14.97%
Education 907 2.39%
Government/Politics 469 1.23%
Business Services 279 0.73%
Finance 244 0.64%
Manufacturing 149 0.39%
Retail 130 0.34%
Healthcare/Wellness 104 0.27%
Transportation 103 0.27%

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