CVE-2026-87022
Published:September 23, 2026
Updated:September 24, 2026
Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121.
The following versions were EOS at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.56 through 7.0.109. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.1.22, which fix the issue.
Affected Packages
https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=9.0.0-M1 <9.0.122Fix Suggestion:
Update to version 9.0.122https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=11.0.0-M1 <11.0.26Fix Suggestion:
Update to version 11.0.26https://github.com/apache/tomcat.git (GITHUB):
Affected version(s) >=10.1.0-M1 <10.1.60Fix Suggestion:
Update to version 10.1.60org.apache.tomcat:tomcat-websocket (JAVA):
Affected version(s) >=10.1.0-M1 <10.1.60Fix Suggestion:
Update to version 10.1.60org.apache.tomcat:tomcat-websocket (JAVA):
Affected version(s) >=9.0.0.M1 <9.0.122Fix Suggestion:
Update to version 9.0.122org.apache.tomcat:tomcat-websocket (JAVA):
Affected version(s) >=11.0.0-M1 <11.0.26Fix Suggestion:
Update to version 11.0.26org.apache.tomcat.embed:tomcat-embed-websocket (JAVA):
Affected version(s) >=11.0.0-M1 <11.0.26Fix Suggestion:
Update to version 11.0.26org.apache.tomcat.embed:tomcat-embed-websocket (JAVA):
Affected version(s) >=10.1.0-M1 <10.1.60Fix Suggestion:
Update to version 10.1.60org.apache.tomcat.embed:tomcat-embed-websocket (JAVA):
Affected version(s) >=9.0.0.M1 <9.0.122Fix Suggestion:
Update to version 9.0.122Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Handling of Length Parameter Inconsistency
EPSS
Base Score:
0.42