Bug#1149964: undertow: CVE-2026-5680

[Salvatore Bonaccorso]

Source: undertow
Version: 2.3.20-1
X-Debbugs-CC: team at security.debian.org
Severity: important
Tags: security upstream

Hi,

The following vulnerability was published for undertow.

CVE-2026-5680[0]:
| 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.


If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-5680
    https://www.cve.org/CVERecord?id=CVE-2026-5680
[1] https://bugzilla.redhat.com/show_bug.cgi?id=2455350

Regards,
Salvatore