HTTP Request Smuggling Affecting org.apache.tomcat.embed:tomcat-embed-core package, versions [9.0.118,9.0.122)[10.1.55,10.1.60)[11.0.22,11.0.26)


Severity

Recommended
0.0
critical
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.48% (42nd percentile)

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  • Snyk IDSNYK-JAVA-ORGAPACHETOMCATEMBED-21716509
  • published26 Oct 2026
  • disclosed23 Sept 2026
  • creditJeppe Weikop

Introduced: 23 Sep 2026

CVE-2026-86350  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade org.apache.tomcat.embed:tomcat-embed-core to version 9.0.122, 10.1.60, 11.0.26 or higher.

Overview

org.apache.tomcat.embed:tomcat-embed-core is a Core Tomcat implementation.

Affected versions of this package are vulnerable to HTTP Request Smuggling via inconsistent HTTP/2 header decoding in HpackDecoder and header processing in Stream. An attacker can trigger a request-header mix-up by sending crafted HTTP/2 headers, causing Tomcat to interpret requests inconsistently; this regression was introduced by the fix for CVE-2026-41293.

CVSS Base Scores

version 4.0
version 3.1