Description
The refactoring present in Apache Tomcat 9.0.28 to 9.0.30, 8.5.48 to 8.5.50 and 7.0.98 to 7.0.99 introduced a regression. The result of the regression was that invalid Transfer-Encoding headers were incorrectly processed leading 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 products
apache: tomcat; apache: tomee; opensuse: leap; netapp: data availability services; netapp: oncommand system manager; debian: debian linux; oracle: agile engineering data management; oracle: agile product lifecycle management; oracle: communications instant messaging server; oracle: health sciences empirica inspections; oracle: health sciences empirica signal; oracle: hospitality guest access; oracle: instantis enterprisetrack; oracle: mysql enterprise monitor; oracle: transportation management
References10
- lists.apache.org/thread.html/r88def002c5c78534674ca67472e035099… Mailing ListVendor Advisory
- lists.apache.org/thread.html/r88def002c5c78534674ca67472e035099… Mailing ListVendor Advisory
- www.oracle.com/security-alerts/cpujan2021.html PatchThird Party Advisory
- www.oracle.com/security-alerts/cpujul2020.html PatchThird Party Advisory
- www.oracle.com/security-alerts/cpuoct2020.html PatchThird Party Advisory
- www.oracle.com/security-alerts/cpujan2021.html PatchThird Party Advisory
- www.oracle.com/security-alerts/cpujul2020.html PatchThird Party Advisory
- www.oracle.com/security-alerts/cpuoct2020.html PatchThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2020-03/msg00025.… Mailing ListThird Party Advisory
- lists.apache.org/thread.html/r7bc994c965a34876bd94d5ff15b4e1e30…
Metrics
- CVSS 3.1
-
4.8
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N - EPSS — exploit probability
- 9% percentile: 95 · as of 6 November 2026
- CWE
- CWE-444
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.