Apache Tomcat WS Async Timeout DoS (v9.0.0.M19.0.121,10.1.0.M110.1.59,11.0.0-M111.0.25)
CVE-2026-79677 Published on September 23, 2026
Apache Tomcat: WebSocket DoS due to lost asynchronous write timeout
Missing release of resource after effective lifetime, Comparison using wrong factors vulnerability in Apache Tomcat allows a denial of service as a result of lost time outs for asynchronous WebSocket writes.
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 EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 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 9.0.122, which fix the issue.
Weakness Types
Missing Release of Resource after Effective Lifetime
The software does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed. When a resource is not released after use, it can allow attackers to cause a denial of service by causing the allocation of resources without triggering their release. Frequently-affected resources include memory, CPU, disk space, power or battery, etc.
Comparison Using Wrong Factors
The code performs a comparison between two entities, but the comparison examines the wrong factors or characteristics of the entities, which can lead to incorrect results and resultant weaknesses. This can lead to incorrect results and resultant weaknesses. For example, the code might inadvertently compare references to objects, instead of the relevant contents of those objects, causing two "equal" objects to be considered unequal.
Products Associated with CVE-2026-79677
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Affected Versions
Apache Software Foundation Apache Tomcat:- Version 11.0.0-M1, <= 11.0.25 is affected.
- Version 10.1.0-M1, <= 10.1.59 is affected.
- Version 9.0.0.M1, <= 9.0.121 is affected.
- Version 8.5.0, <= 8.5.100 is affected.
- Version 7.0.43, <= 7.0.109 is affected.
- Before 7.0.43 is unaffected.