CVE-2026-42009: vLLM — HIGH

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This...

Full CISO analysis pending enrichment.

What systems are affected?

Package	Ecosystem	Vulnerable Range	Patched
vLLM	pip	—	No patch
85.4K 129 dependents Pushed yesterday 22% patched ~51d to patch Full package profile →
discovery/discovery-server-rhel9	—	—	No patch
discovery/discovery-ui-rhel9	—	—	No patch
gnutls	—	—	No patch
gnutls-main	—	—	No patch
libtasn1	—	—	No patch
rhaiis/model-opt-cuda-rhel9	—	—	No patch
rhcos	—	—	No patch
rhui5/cds-rhel9	—	—	No patch
rhui5/haproxy-rhel9	—	—	No patch
rhui5/installer-rhel9	—	—	No patch
rhui5/rhua-rhel9	—	—	No patch

How severe is it?

CVSS 3.1

7.5 / 10

EPSS

N/A

Exploitation Status

No known exploitation

Sophistication

N/A

What is the attack surface?

AV Network

AC Low

PR None

UI None

S Unchanged

C None

I None

A High

What should I do?

No patch available

Monitor for updates. Consider compensating controls or temporary mitigations.

Which compliance frameworks are affected?

Compliance analysis pending. Sign in for full compliance mapping when available.

Frequently Asked Questions

What is CVE-2026-42009?

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.

Is CVE-2026-42009 actively exploited?

No confirmed active exploitation of CVE-2026-42009 has been reported, but organizations should still patch proactively.

How to fix CVE-2026-42009?

No patch is currently available. Monitor vendor advisories for updates.

What is the CVSS score for CVE-2026-42009?

CVE-2026-42009 has a CVSS v3.1 base score of 7.5 (HIGH).

What are the technical details?

Original Advisory

A flaw was found in gnutls. A remote attacker could exploit an issue in the Datagram Transport Layer Security (DTLS) packet reordering logic. The comparator function, responsible for ordering DTLS packets by sequence numbers, did not correctly handle packets with duplicate sequence numbers. This could lead to unstable packet ordering or undefined behavior, resulting in a denial of service.

Weaknesses (CWE)

CWE-475 Undefined Behavior for Input to API

CWE-475 — Undefined Behavior for Input to API: The behavior of this function is undefined unless its control parameter is set to a specific value.

Source: MITRE CWE corpus.