CVE-2026-5680

HIGH
MEDIUM Priority: 0.08 BB Relevance: 75/100
Published: 2026-08-27 Modified: 2026-11-04 First seen: 2026-11-04 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

Description

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.

References & Advisories (6)

https://access.redhat.com/errata/RHSA-2026:70228
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:70229
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:70230
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:70277
vendor-advisory x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2455350
issue-tracking x_refsource_REDHAT

Bug Bounty Relevance

75 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

7.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

1.10%
Raw Score 0.010960
Percentile 66.1%
Date 2026-11-14

EPSS Trend

2026-11-14
0.01096
2026-11-13
0.01096
2026-11-12
0.01096
2026-11-10
0.01096
2026-11-09
0.01096
2026-11-08
0.01096
2026-11-07
0.01096
2026-11-06
0.01096
2026-11-05
0.01096
2026-11-04
0.01096

Intelligence Sources

mitre ref →
nvd ref →