WebSocket Vulnerability in Undertow Affects Multiple Applications
CVE-2026-5680

7.5HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Build Of Apache Camel For Spring Boot 4
Red Hat Build Of Apache Camel - Hawtio 4
Red Hat Data Grid 8
Red Hat Enterprise Linux 10
Vendor
CVE Published:
27 August 2026

What is CVE-2026-5680?

A security issue has been identified in Undertow where a remote attacker can exploit the vulnerability by sending specially crafted WebSocket messages that negotiate the permessage-deflate extension. This flaw can lead to excessive memory consumption due to the underlying PerMessageDeflateFunction.largerBuffer() method utilizing an exponential doubling algorithm. As a result, applications using the affected version may experience a Denial of Service (DoS), rendering them unavailable to legitimate users. It is crucial for organizations to evaluate their use of Undertow and apply necessary security measures to mitigate this risk.

References

https://access.redhat.com/security/cve/CVE-2026-5680
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2455350
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Red Hat would like to thank Avishek Sarkar and Brian Laub for reporting this issue.
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