HIGH · 7.5

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 pac...

Vulnerability Description

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.

CVSS Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH

Affected Products

VendorProductVersions
GnuGnutls-
RedhatHardened Images-
RedhatOpenshift Container Platform4.0
RedhatEnterprise Linux6.0
RedhatEnterprise Linux For Els8.10
RedhatEnterprise Linux For Ibm Z Systems8.0_s390x
RedhatEnterprise Linux For Ibm Z Systems Els8.10
RedhatEnterprise Linux For Power Little Endian8.0_ppc64le
RedhatEnterprise Linux For Power Little Endian Els8.10
RedhatEnterprise Linux For Eus9.8
RedhatEnterprise Linux For Ibm Z Systems Eus9.8
RedhatEnterprise Linux For Power Little Endian Eus9.8
RedhatEnterprise Linux For Update Services For Sap Solutions9.8
RedhatEnterprise Linux Server For Power Little Endian Update Services For Sap Solutions9.8

Related Weaknesses (CWE)

References

FAQ

What is CVE-2026-42009?

CVE-2026-42009 is a vulnerability with a CVSS score of 7.5 (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 pac...

How severe is CVE-2026-42009?

CVE-2026-42009 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42009?

Check the references section above for vendor advisories and patch information. Affected products include: Gnu Gnutls, Redhat Hardened Images, Redhat Openshift Container Platform, Redhat Enterprise Linux, Redhat Enterprise Linux For Els.