Apache Tomcat Open Redirect vulnerability

Exploitation

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

CVSS

4.3 · CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

EPSS

• CVE-2018-11784: 97.68% estimated exploitation activity in the next 30 days; percentile 99.90 (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.

When the default servlet in Apache Tomcat versions 9.0.0.M1 to 9.0.11, 8.5.0 to 8.5.33 and 7.0.23 to 7.0.90 returned a redirect to a directory (e.g. redirecting to '/foo/' when the user requested '/foo') a specially crafted URL could be used to cause the redirect to be generated to any URI of the attackers choice.

Published by the source

17 Oct 2018, 16:31 UTC

Last modified by the source

22 Feb 2024, 22:43 UTC

Source last checked

26 Oct 2026, 16:26 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5q99-f34m-67gc

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# Patch Next advisory brief: CVE-2018-11784

Advisory: Apache Tomcat Open Redirect vulnerability
IDs: CVE-2018-11784, GHSA-5q99-f34m-67gc
Record: https://patchnext.com/advisories/cve-2018-11784 (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 4.3)
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 9.0.12, 8.5.34, 7.0.91. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven org.apache.tomcat.embed:tomcat-embed-core: affected >= 8.5.0, < 8.5.34; >= 7.0.23, < 7.0.91; >= 9.0.0, < 9.0.12; fixed in 7.0.91, 8.5.34, 9.0.12

## 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-5q99-f34m-67gc (GitHub-reviewed advisory GHSA-5q99-f34m-67gc lists affected ranges: Maven org.apache.tomcat.embed:tomcat-embed-core >=8.5.0 =7.0.23 =9.0.0 <9.0.12)

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