CVE & CISA-KEV CatalogNVD
CVE-2026-42009
MEDIUM7.5
CVSS v3
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.
How to fix
Remediation Available
gnutlsAmazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-c++Amazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-c++-debuginfoAmazon
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-daneAmazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-dane-debuginfoAmazon
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-debuginfoAmazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-debugsourceAmazon
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-develAmazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-utilsAmazon
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.3.29-9.amzn2.0.4
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls-utils-debuginfoAmazon
Fixed in:0:3.8.3-8.amzn2023.0.3
Fixed in:0:3.8.3-8.amzn2023.0.3
gnutls28Debian
Fixed in:3.7.9-2+deb12u7CVE-2026-42009
Fixed in:3.8.9-3+deb13u4CVE-2026-42009
Fixed in:3.8.13-1CVE-2026-42009
gnutlsRed Hat / RHEL
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutlsRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-c++Rocky
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-c++Red Hat / RHEL
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-c++-debuginfoRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-c++-debuginfoRed Hat / RHEL
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-daneRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-daneRed Hat / RHEL
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-dane-debuginfoRocky
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-dane-debuginfoRed Hat / RHEL
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-debuginfoRed Hat / RHEL
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-debuginfoRocky
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-debugsourceRed Hat / RHEL
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-debugsourceRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-develRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-develRed Hat / RHEL
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-fipsRed Hat / RHEL
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
gnutls-fipsRocky
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
gnutls-utilsRed Hat / RHEL
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.10-4.el10_2RHSA-2026:20613
Fixed in:0:3.8.9-9.el10_0.19RHSA-2026:26409
This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:R
Exploit Intelligence
1.33%probability of exploitation in 30 days
70thpercentile
Moderate risk: more likely to be exploited than 70% of all known CVEs.
References
Third-Party Advisory6
Other references27
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- gnutls.org
- security.access.redhat.com
Related Vulnerabilities
Other CWE-475 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-7925 | High | 7.5 | 1.7% | - | Fix |
| CVE-2025-47865 | High | 7.5 | 1.7% | - | - |
| CVE-2024-20380 | High | 7.5 | 1.1% | - | - |
| CVE-2023-2253 | Medium | 6.5 | 0.9% | - | Fix |
| CVE-2023-4874 | Medium | 4.3 | 0.8% | - | Fix |
| CVE-2024-10569 | High | 7.5 | 0.6% | - | - |
Common questions
How do I fix CVE-2026-42009?
Published advisories record a fix for 79 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.
Is CVE-2026-42009 being actively exploited?
Not that we know of. CVE-2026-42009 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 1.3% is the estimated probability that it will be exploited in the next 30 days. That is higher than 70% of all scored CVEs.
How severe is CVE-2026-42009?
CVE-2026-42009 has a CVSS v3 base score of 7.5, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-42009 affect?
Published advisories record a fix for gnutls (Amazon), gnutls-c++ (Amazon), gnutls-c++-debuginfo (Amazon), gnutls-dane (Amazon), and 75 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-42009
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-18.