CVE-2026-5680

highpriority · track · 30EPSS 0.011 · 65 %ileDEUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.10% (65th) EPSS

CVSS 7.5 · high

Is it mine?

2 products

Check your exposure

Who says so?

1 sources

cert_bund

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · secalert@redhat.com USexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-770US

affected products (2)

Products and version ranges known to be affected.

Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Undertowall versionscert_bundDEcpe:/a:redhat:undertow:-

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-3059Red Hat Undertow: Schwachstelle ermöglicht Denial of ServiceDeutsch2026-08-27csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Red Hat Undertow ausnutzen, um einen Denial of Service Angriff durchzuführen.

sources

Which sources assert this record, and when.

cert_bund NVD CVE.org MITRE

published 2026-08-27modified 2026-10-20

references (6) nvd

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

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