CVE-2026-5680

7.5 HIGH 1% exploit odds No fix listed Denial of service

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in. High risk of service disruption.
Exploit odds: 1.1% chance of exploitation in the next 30 days (EPSS).
Fix: No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

2026-08-27 17:18 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-11-04 23:17 UTC Last updatedMost recent change to the record

Details

Published: 2026-08-27 17:18 UTC
Last modified: 2026-11-04 23:17 UTC
Exploit probability: 1.1% · EPSS, next 30 days
Weakness: CWE-770 · Allocation without limits
Record status: Awaiting Analysis

Attack profile CVSS 3.1 · 7.5

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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References

NVD record · CVE.org record