Apache Tomcat Race Condition vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.9 · CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2018-8037: 11.16% estimated exploitation activity in the next 30 days; percentile 95.95 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

If an async request was completed by the application at the same time as the container triggered the async timeout, a race condition existed that could result in a user seeing a response intended for a different user. An additional issue was present in the NIO and NIO2 connectors that did not correctly track the closure of the connection when an async request was completed by the application and timed out by the container at the same time. This could also result in a user seeing a response intended for another user. Versions Affected: Apache Tomcat 9.0.0.M9 to 9.0.9 and 8.5.5 to 8.5.31.

Published by the source

17 Oct 2018, 16:33 UTC

Last modified by the source

22 Feb 2024, 21:06 UTC

Source last checked

26 Oct 2026, 16:26 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6v52-mj5r-7j2m

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# Patch Next advisory brief: CVE-2018-8037

Advisory: Apache Tomcat Race Condition vulnerability
IDs: CVE-2018-8037, GHSA-6v52-mj5r-7j2m
Record: https://patchnext.com/advisories/cve-2018-8037 (revision 1, source checked 26 Oct 2026, 16:26 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: org.apache.tomcat.embed:tomcat-embed-core 9.0.10, 8.5.32. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.tomcat.embed:tomcat-embed-core: affected >= 8.5.5, < 8.5.32; >= 9.0.0.M9, < 9.0.10; fixed in 8.5.32, 9.0.10

## Suggested inspection (read-only)
- Maven org.apache.tomcat.embed:tomcat-embed-core: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on org.apache.tomcat.embed:tomcat-embed-core.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6v52-mj5r-7j2m (GitHub-reviewed advisory GHSA-6v52-mj5r-7j2m lists affected ranges: Maven org.apache.tomcat.embed:tomcat-embed-core >=8.5.5 =9.0.0.M9 <9.0.10)

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