CVE-2025-52520: Apache Tomcat: DoS via integer overflow in multipart file upload

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-10 · updated 2026-06-17
Weakness: CWE-190

Description

For some unlikely configurations of multipart upload, an Integer Overflow vulnerability in Apache Tomcat could lead to a DoS via bypassing of size limits. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.8, from 10.1.0-M1 through 10.1.42, from 9.0.0.M1 through 9.0.106. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Other, older, EOL versions may also be affected. Users are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.

Affected products

Apache Tomcat: from 9.0.0 before 9.0.107; from 10.1.0 before 10.1.43; from 11.0.0 before 11.0.9 — fixed in 10.1.43, 11.0.9, 9.0.107

How to fix

Upgrade to a fixed version: Apache Tomcat 10.1.43, 11.0.9, 9.0.107. Check the vendor advisory for mitigations.

References

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