CVE-2026-42009
Gnutls: gnutls: denial of service via dtls packet reordering 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.
INFO
Published Date :
May 18, 2026, 1:16 p.m.
Last Modified :
June 8, 2026, 5:16 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-42009
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 53f830b8-0a3f-465b-8143-3b8a9948e749 | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update gnutls to the latest version.
- Apply relevant security patches for gnutls.
- Verify packet handling logic.
Public PoC/Exploit Available at Github
CVE-2026-42009 has a 3 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42009.
| URL | Resource |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:13274 | Third Party Advisory |
| https://access.redhat.com/errata/RHSA-2026:20611 | Third Party Advisory |
| https://access.redhat.com/errata/RHSA-2026:20612 | Third Party Advisory |
| https://access.redhat.com/errata/RHSA-2026:20613 | Third Party Advisory |
| https://access.redhat.com/security/cve/CVE-2026-42009 | Third Party Advisory |
| https://bugzilla.redhat.com/show_bug.cgi?id=2467279 | Issue Tracking Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42009 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42009
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
ollama based on v0.36.0 - fixed all CVE
None
Dockerfile Shell Makefile Python
None
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42009 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42009 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 08, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* *cpe:2.3:a:gnu:gnutls:-:*:*:*:*:*:*:* *cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:* *cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:8.0_ppc64le:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:8.0_s390x:*:*:*:*:*:*:* *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_els:8.10:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:8.10:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:9.0_ppc64le:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:* *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_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_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:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:9.0_s390x:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:arm64:* *cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:arm64:* *cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:arm64:* *cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:arm64:* *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:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.0:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.2:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:x64:* *cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:x64:* *cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:x64:* *cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:x64:* *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:10.2:*:*:*:*:*:*:* *cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:10.2:*:*:*:*:*:*:* Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:13274 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:20611 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:20612 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/errata/RHSA-2026:20613 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://access.redhat.com/security/cve/CVE-2026-42009 Types: Third Party Advisory Added Reference Type Red Hat, Inc.: https://bugzilla.redhat.com/show_bug.cgi?id=2467279 Types: Issue Tracking, Third Party Advisory -
CVE Modified by [email protected]
Jun. 02, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:20612 -
CVE Modified by [email protected]
Jun. 01, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:20613 -
CVE Modified by [email protected]
May. 27, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:20611 -
CVE Modified by [email protected]
May. 24, 2026
Action Type Old Value New Value Added Reference https://access.redhat.com/errata/RHSA-2026:13274 -
New CVE Received by [email protected]
May. 18, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-475 Added Reference https://access.redhat.com/security/cve/CVE-2026-42009 Added Reference https://bugzilla.redhat.com/show_bug.cgi?id=2467279