Improper Handling of Length Parameter Inconsistency Affecting org.apache.tomcat.embed:tomcat-embed-websocket package, versions [9.0.0.M1,9.0.122)[10.1.0-M1,10.1.60)[11.0.0-M1,11.0.26)


Severity

Recommended
0.0
medium
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.54% (46th percentile)

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  • Snyk IDSNYK-JAVA-ORGAPACHETOMCATEMBED-21715428
  • published26 Oct 2026
  • disclosed23 Sept 2026
  • creditkrsecurity

Introduced: 23 Sep 2026

CVE-2026-87022  (opens in a new tab)
CWE-130  (opens in a new tab)

How to fix?

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

Overview

Affected versions of this package are vulnerable to Improper Handling of Length Parameter Inconsistency via the getMoreData method in the PerMessageDeflate transformation. An attacker can send a per-message-deflate payload containing multiple DEFLATE blocks where a block sets BFINAL before later blocks; Tomcat may end processing while compressed bytes remain, causing message data to be ignored and allowing message contents to be smuggled. This affects WebSocket connections using per-message-deflate.

CVSS Base Scores

version 4.0
version 3.1