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HIGH severity

CVE-2025-52520 — tomcat-catalina

HIGHFix: apache/tomcat@927d66f

CVE-2025-52520 is a high-severity (CVSS 7.5) CWE-190 vulnerability in org.apache.tomcat:tomcat-catalina. A fix is available for org.apache.tomcat:tomcat-catalina — see the affected versions and patch details below.

Apache Tomcat: DoS via integer overflow in multipart file upload

Also known asBIT-tomcat-2025-52520GHSA-wr62-c79q-cv37
Published
Updated
Affected
8 pkgs
Patched
6 / 8
Exploits
None indexed
Exploitation data as of Nov 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2025-52520.

EPSS Exploitation Probability

via FIRST.org ↗
2.2%probability of exploitation in next 30 days
Lower Risk+0.10%
Lower risk than most CVEs83th percentile — riskier than 83% of all scored CVEsHighest risk
0.18%1.02%1.86%2.70%0.7%2.2%Jun 26Sep 26Nov 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

8 pkgs affected
☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat:tomcat-catalina☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core☕org.apache.tomcat.embed:tomcat-embed-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

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 Packages

8 total 6 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenorg.apache.tomcat:tomcat-catalina≥ 11.0.0-M1&&< 11.0.911.0.9org.apache.tomcat:tomcat-catalina:11.0.9
☕Mavenorg.apache.tomcat:tomcat-catalina≥ 10.1.0-M1&&< 10.1.4310.1.43org.apache.tomcat:tomcat-catalina:10.1.43
☕Mavenorg.apache.tomcat:tomcat-catalina≥ 9.0.0.M1&&< 9.0.1079.0.107org.apache.tomcat:tomcat-catalina:9.0.107
☕Mavenorg.apache.tomcat:tomcat-catalina≥ 8.5.0No fix
☕Mavenorg.apache.tomcat.embed:tomcat-embed-core≥ 11.0.0-M1&&< 11.0.911.0.9org.apache.tomcat.embed:tomcat-embed-core:11.0.9
☕Mavenorg.apache.tomcat.embed:tomcat-embed-core≥ 10.1.0-M1&&< 10.1.4310.1.43org.apache.tomcat.embed:tomcat-embed-core:10.1.43

Affected Products

1 product · 3 configurations
Application
tomcatapache
≥ 11.0.0 && < 11.0.9
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat-catalina, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update org.apache.tomcat:tomcat-catalina to 11.0.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-52520 is resolved across your whole dependency graph.

  3. Workarounds

    Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow
Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for CVE-2025-52520 (CC BY 4.0)
ProductFixed inAdvisory
Red Hat Enterprise Linux 10tomcat9-1:9.0.87-5.el10_0.3RHSA-2025:14178
Red Hat Enterprise Linux 10tomcat-1:10.1.36-1.el10_0.2RHSA-2025:14179
Red Hat Enterprise Linux 8tomcat-1:9.0.87-1.el8_10.6RHSA-2025:14177
Red Hat Enterprise Linux 8.8 Telecommunications Update Servicetomcat-1:9.0.87-1.el8_8.7RHSA-2025:14182
Red Hat Enterprise Linux 9tomcat-1:9.0.87-3.el9_6.3RHSA-2025:14181
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutionstomcat-1:9.0.87-1.el9_2.6RHSA-2025:14183
Red Hat Enterprise Linux 9.4 Extended Update Supporttomcat-1:9.0.87-1.el9_4.6RHSA-2025:14180
Red Hat JBoss Web Server 5.8.5jws5-tomcatRHSA-2025:11696

Frequently Asked Questions

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.
O3 Security · Impact-Aware SCA

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CVE-2025-52520: tomcat-catalina DoS — Fixed in 11.0.9