Improper Handling of Length Parameter Inconsistency Affecting org.apache.tomcat:tomcat-websocket package, versions [9.0.0.M1,9.0.122)[10.1.0-M1,10.1.60)[11.0.0-M1,11.0.26)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ORGAPACHETOMCAT-21715427
- published26 Oct 2026
- disclosed23 Sept 2026
- creditkrsecurity
Introduced: 23 Sep 2026
CVE-2026-87022 (opens in a new tab)How to fix?
Upgrade org.apache.tomcat:tomcat-websocket to version 9.0.122, 10.1.60, 11.0.26 or higher.
Overview
org.apache.tomcat:tomcat-websocket is a Tomcat WebSocket (JSR356) implementation.
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.