CVE-2011-1475 Apache Tomcat HTTP BIO Connector Error Discloses Information From Different Requests to Remote Users

What is CVE-2011-1475?

CVE-2011-1475 is a medium-severity vulnerability in Apache Tomcat, published on 8 Apr 2011. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The HTTP BIO connector in Apache Tomcat 7.0.x before 7.0.12 does not properly handle HTTP pipelining, which allows remote attackers to read responses intended for other clients in opportunistic circumstances by examining the application data in HTTP packets, related to "a mix-up of responses for requests from different users."

Weakness: CWE-20

Which versions are affected by CVE-2011-1475?

2 open source packages ship an affected version, including org.apache.tomcat:tomcat. It affects 1 product.

Products include Apache Tomcat.

How do I fix CVE-2011-1475?

Upgrade org.apache.tomcat:tomcat to 7.0.12 or later.

Is CVE-2011-1475 being exploited?

There is no known exploitation of CVE-2011-1475 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in Apache Tomcat

• CVE-2025-24813 Apache Tomcat Path Equivalence Exploited Critical 10.0
• CVE-2016-8735 Apache Tomcat Remote Code Execution Exploited Critical 9.8
• CVE-2017-12617 Apache Tomcat Remote Code Execution Exploited High 8.1
• CVE-2017-12615 Apache Tomcat on Windows Remote Code Execution Exploited High 8.1
• CVE-2026-34486 Apache Tomcat Missing Encryption of Sensitive Data Exploited High 7.5

All Apache Tomcat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-h6c8-rg87-f3pc.