CVE-2026-5680CWE-770denial-of-service

CVE-2026-5680

High · published August 27, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
65.3
In the wild
Unconfirmed
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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.01096 · 65.3th percentile
Weakness
CWE-770 · Allocation of Resources Without Limits or Throttling
Published
2026-08-27T21:18Z
References (6)
https://access.redhat.com/errata/RHSA-2026:70228 · [email protected]https://access.redhat.com/errata/RHSA-2026:70229 · [email protected]https://access.redhat.com/errata/RHSA-2026:70230 · [email protected]https://access.redhat.com/errata/RHSA-2026:70277 · [email protected]https://access.redhat.com/security/cve/CVE-2026-5680 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2455350 · [email protected]
EPSS history
Timeline
  • 27 AUG 16:25Z
    Undertow-core: undertow: denial of service via websocket permessage-deflate processing
    cvelistv5