CVE-2026-42009
Gnutls: gnutls: denial of service via dtls packet reordering vulnerability
Published May 18, 2026 · updated Oct 14, 2026 · gnu gnutls
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.
Timeline
Detection, updates, and resolution for this record.
May 18, 2026 · Catalog
Detected
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.
Oct 14, 2026 · Catalog
Updated
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.
Oct 14, 2026 · NIST NVD
Updated
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.
Affected
- cpe gnu/gnutlsversion unspecified
- cpe redhat/enterprise linux10.0
- cpe redhat/enterprise linux6.0
- cpe redhat/enterprise linux7.0
- cpe redhat/enterprise linux8.0
- cpe redhat/enterprise linux9.0
- cpe redhat/enterprise linux for els8.10
- cpe redhat/hardened imagesversion unspecified
- cpe redhat/openshift container platform4.0
- vendor Red Hat Red Hat Enterprise Linux 10version unspecified
- vendor Red Hat Red Hat Enterprise Linux 10.0 Extended Update Supportversion unspecified
- vendor Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Supportversion unspecified
- vendor Red Hat Red Hat Enterprise Linux 8version unspecified
- vendor Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Supportversion unspecified
Sources
- CIRCL Vulnerability LookupCVE-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 sequen
vulnerability.circl.lu - CVE.orgCVE-2026-42009
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-42009
30-day exploitation probability 1.1%
first.org - NIST NVDCVE-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 sequen
nvd.nist.gov