# CVE-2018-11784: Apache Tomcat Open Redirect vulnerability > Attackers can craft URLs to redirect users to arbitrary external sites via the default servlet, potentially facilitating phishing attacks. - **Severity:** Medium 4.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 4 Oct 2018 - **Updated:** 15 Oct 2026 - **Also known as:** DLA-1544-1, DLA-1545-1, GHSA-5q99-f34m-67gc, RHSA-2019:0485, SUSE-SU-2018:3393-1, SUSE-SU-2018:3935-1, SUSE-SU-2018:3968-1, UBUNTU-CVE-2018-11784, USN-3787-1 ## What is CVE-2018-11784? CVE-2018-11784 is a medium-severity vulnerability in Apache Tomcat, published on 4 Oct 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### Official description 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. Weakness: CWE-601 (URL Redirection to Untrusted Site) ## Which versions are affected by CVE-2018-11784? 6 open source packages ship an affected version, including org.apache.tomcat.embed:tomcat-embed-core. It affects 15 products. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 7.0.23 | 7.0.91 | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 7.0.23 | 7.0.91 | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 8.5.0 | 8.5.34 | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 8.5.0 | 8.5.34 | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 9.0.0 | 9.0.12 | | `org.apache.tomcat.embed:tomcat-embed-core` | Maven | From 9.0.0 | 9.0.12 | | `tomcat` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-admin-webapps` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-docs-webapp` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-el-2.2-api` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-javadoc` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsp-2.2-api` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsvc` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-lib` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-servlet-3.0-api` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat-webapps` | Red Hat:enterprise_linux:7::client | All versions | 0:7.0.76-9.el7_6 | | `tomcat` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-admin-webapps` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-docs-webapp` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-el-2.2-api` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-javadoc` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsp-2.2-api` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsvc` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-lib` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-servlet-3.0-api` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat-webapps` | Red Hat:enterprise_linux:7::computenode | All versions | 0:7.0.76-9.el7_6 | | `tomcat` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-admin-webapps` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-docs-webapp` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-el-2.2-api` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-javadoc` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsp-2.2-api` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-jsvc` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-lib` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-servlet-3.0-api` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat-webapps` | Red Hat:enterprise_linux:7::server | All versions | 0:7.0.76-9.el7_6 | | `tomcat` | Red Hat:enterprise_linux:7::workstation | All versions | 0:7.0.76-9.el7_6 | | `tomcat-admin-webapps` | Red Hat:enterprise_linux:7::workstation | All versions | 0:7.0.76-9.el7_6 | | `tomcat-docs-webapp` | Red Hat:enterprise_linux:7::workstation | All versions | 0:7.0.76-9.el7_6 | | `tomcat-el-2.2-api` | Red Hat:enterprise_linux:7::workstation | All versions | 0:7.0.76-9.el7_6 | Products: Apache Tomcat, Canonical Ubuntu Linux, Debian Debian Linux, Netapp Snap Creator Framework, Oracle Communications Application Session Controller, Oracle Hospitality Guest Access, Oracle Instantis Enterprisetrack, Oracle Retail Order Broker, Oracle Secure Global Desktop, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux Server, Redhat Enterprise Linux Server Aus, Redhat Enterprise Linux Server Eus, Redhat Enterprise Linux Server Tus, Redhat Enterprise Linux Workstation. ## How do I fix CVE-2018-11784? Upgrade org.apache.tomcat.embed:tomcat-embed-core to a fixed version for your release line: 7.0.91, 8.5.34 or 9.0.12. ## Is CVE-2018-11784 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-11784 exists. Public exploit code: - Apache Tomcat 9.0.0.M1 - Open Redirect (exploitdb) - Apache Tomcat - Open Redirect (github_poc): https://github.com/Cappricio-Securities/CVE-2018-11784 - Apache Tomcat - Open Redirect (nuclei): http/cves/2018/CVE-2018-11784.yaml ## Other vulnerabilities in Apache Tomcat - [CVE-2025-24813](https://insights.sbomify.com/CVE-2025-24813/): Apache Tomcat Path Equivalence (critical 10.0, exploited in the wild) - [CVE-2016-8735](https://insights.sbomify.com/CVE-2016-8735/): Apache Tomcat Remote Code Execution (critical 9.8, exploited in the wild) - [CVE-2017-12617](https://insights.sbomify.com/CVE-2017-12617/): Apache Tomcat Remote Code Execution (high 8.1, exploited in the wild) - [CVE-2017-12615](https://insights.sbomify.com/CVE-2017-12615/): Apache Tomcat on Windows Remote Code Execution (high 8.1, exploited in the wild) - [CVE-2026-34486](https://insights.sbomify.com/CVE-2026-34486/): Apache Tomcat Missing Encryption of Sensitive Data (high 7.5, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2018-11784 and fix it if it is affected. What it is: CVE-2018-11784 is a medium-severity vulnerability in Apache Tomcat, published on 4 Oct 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-11784 exists. Affected packages and fixed versions: - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 7.0.23; fixed in 7.0.91 - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 7.0.23; fixed in 7.0.91 - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 8.5.0; fixed in 8.5.34 - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 8.5.0; fixed in 8.5.34 - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 9.0.0; fixed in 9.0.12 - org.apache.tomcat.embed:tomcat-embed-core (Maven): affected from 9.0.0; fixed in 9.0.12 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2018-11784/ (Markdown: https://insights.sbomify.com/CVE-2018-11784/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2018-11784 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-11784 - OSV: https://osv.dev/vulnerability/CVE-2018-11784 --- From sbomify Insights: https://insights.sbomify.com/CVE-2018-11784/ Summaries are generated and may contain mistakes; the official description above is the record.