CVE WatchOct 8, 2026

CVE-2020-1935

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 parsin

CVSS

4.8

Medium

EPSS

9.4%

p95

KEV

—

Exploit Today

0-100

Published: Feb 24, 2020 · Last modified: Oct 8, 2026 · CWE-444

EPSS · 30d

9.4%EPSS · 30 days9.4%

2026-09-302026-10-28

Technical description

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.

Official references

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