CVE-2026-42009

Gnutls: gnutls: denial of service via dtls packet reordering vulnerability

HIGH 7.5

At a glance

Source: NVD
EPSS: EPSS 1.33 % · percentile 71 (2026-10-28)
State: PUBLISHED
Published: 2026-05-18 12:44 UTC
Updated: 2026-10-26 17:03 UTC
Assigner: redhat
NVD status: Modified

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.

Weaknesses (CWE)

CWE-475

References

Scores

Version	Score	Vector	Scored by
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	redhat-SADP
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · secalert@redhat.com (Secondary)
CVSS 3.1	HIGH 7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary)

European references

ENISA EUVD · EUVD-2026-30769
GCVE · GCVE-0-2026-42009

CERT-FR advisories

CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
CERTFR-2026-AVI-0958 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
CERTFR-2026-AVI-0681 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:*
cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:8.10:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:8.10:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0_s390x:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:8.10:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0_ppc64le:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:8.10:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux:9.8:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:9.8:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:9.8:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_eus:9.8:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_eus:9.8:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:9.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0_ppc64le:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:9.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_update_services_for_sap_solutions:9.8:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.8:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:arm64:*
cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:x64:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:10.2:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:10.2:*:*:*:*:*:*:*
+4 more

Affected products

Product	Versions
gnutls	affected 0 < 3.8.13
Red Hat · Red Hat Enterprise Linux 10	unaffected 0:3.8.10-4.el10_2 < *
Red Hat · Red Hat Enterprise Linux 10.0 Extended Update Support	unaffected 0:3.8.9-9.el10_0.19 < *
Red Hat · Red Hat Enterprise Linux 7 Extended Lifecycle Support	unaffected 0:3.3.29-9.el7_9.1 < *
Red Hat · Red Hat Enterprise Linux 8	unaffected 0:3.6.16-8.el8_10.6 < *
Red Hat · Red Hat Enterprise Linux 8	unaffected 0:3.6.16-8.el8_10.6 < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support	unaffected 0:3.6.14-10.el8_4.1 < *
Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support	unaffected 0:4.13-3.el8_4.1 < *
Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On	unaffected 0:3.6.14-10.el8_4.1 < *
Red Hat · Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On	unaffected 0:4.13-3.el8_4.1 < *
Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support	unaffected 0:3.6.16-5.el8_6.5 < *
Red Hat · Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support	unaffected 0:4.13-3.el8_6.2 < *
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On	unaffected 0:3.6.16-5.el8_6.5 < *
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On	unaffected 0:4.13-3.el8_6.2 < *
Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service	unaffected 0:3.6.16-7.el8_8.4 < *
Red Hat · Red Hat Enterprise Linux 8.8 Telecommunications Update Service	unaffected 0:4.13-4.el8_8.1 < *
Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions	unaffected 0:3.6.16-7.el8_8.4 < *
Red Hat · Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions	unaffected 0:4.13-4.el8_8.1 < *
Red Hat · Red Hat Enterprise Linux 9	unaffected 0:3.8.10-4.el9_8 < *
Red Hat · Red Hat Enterprise Linux 9	unaffected 0:3.8.10-4.el9_8 < *

Sources

Source	Licence
CVE List (CVEProject cvelistV5)	CVE Program Terms of Use
EPSS (FIRST.org)	FIRST — attribution requested
ENISA EUVD	ENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)	Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feeds	Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD