CVE-2026-5680
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using exponential doubling, resulting in a Denial of Service (DoS) for the affected application.
Affected Software
| Vendor | Product | Version Range | Status |
|---|
Weaknesses
- CWE-770: Allocation of Resources Without Limits or Throttling
Workarounds
To mitigate this issue, configure the PerMessageDeflateHandshake to limit the maximum decompressed buffer size. This can be achieved by setting the maxDecompressedBufferSize parameter to a reasonable value (e.g., 10 MB) in the PerMessageDeflateHandshake constructor. This action may require a restart of the affected application or service to take effect.
References
- https://access.redhat.com/security/cve/CVE-2026-5680
- https://bugzilla.redhat.com/show_bug.cgi?id=2455350
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