In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

Affected Packages

Maven org.apache.tomcat.embed:tomcat-embed-core

Affected versions: 0 (fixed in 7.0.100)

Maven org.apache.tomcat.embed:tomcat-embed-core

Affected versions: 8.0.0 (fixed in 8.5.51)

Maven org.apache.tomcat.embed:tomcat-embed-core

Affected versions: 9.0.0 (fixed in 9.0.31)

Maven org.apache.tomcat:tomcat

Affected versions: 0 (fixed in 7.0.100)

Maven org.apache.tomcat:tomcat

Affected versions: 8.0.0 (fixed in 8.5.51)

Maven org.apache.tomcat:tomcat

Affected versions: 9.0.0 (fixed in 9.0.31)

Related CVEs

CVE-2020-1935

Key Information

GHSA ID

GHSA-qxf4-chvg-4r8r

Published

February 28, 2020 1:10 AM

Last Modified

August 19, 2021 7:30 PM

CVSS Score

5.0 /10

Primary Ecosystem

Maven

Primary Package

org.apache.tomcat.embed:tomcat-embed-core

GitHub Reviewed

✓ Yes

Dataset

Last updated: September 10, 2025 6:31 AM

Data from GitHub Advisory Database. This information is provided for research and educational purposes.