CVE-2026-42009 (GCVE-0-2026-42009)

Vulnerability from cvelistv5 – Published: 2026-05-18 12:44 – Updated: 2026-05-27 02:17
VLAI
Title
Gnutls: gnutls: denial of service via dtls packet reordering vulnerability
Summary
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-475 - Undefined Behavior for Input to API
Assigner
References
URL Tags
https://access.redhat.com/errata/RHSA-2026:13274 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:20611 vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-42009 vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2467279 issue-trackingx_refsource_REDHAT
Impacted products
Vendor Product Version
Red Hat Red Hat Enterprise Linux 8 Unaffected: 0:3.6.16-8.el8_10.6 , < * (rpm)
    cpe:/a:redhat:enterprise_linux:8::appstream
    cpe:/o:redhat:enterprise_linux:8::baseos
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Red Hat Red Hat Enterprise Linux 8 Unaffected: 0:3.6.16-8.el8_10.6 , < * (rpm)
    cpe:/a:redhat:enterprise_linux:8::appstream
    cpe:/o:redhat:enterprise_linux:8::baseos
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Red Hat Red Hat Hardened Images Unaffected: 3.8.13-1.hum1 , < * (rpm)
    cpe:/a:redhat:hummingbird:1
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Red Hat Red Hat Enterprise Linux 10     cpe:/o:redhat:enterprise_linux:10
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Red Hat Red Hat Enterprise Linux 6     cpe:/o:redhat:enterprise_linux:6
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Red Hat Red Hat Enterprise Linux 7     cpe:/o:redhat:enterprise_linux:7
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Red Hat Red Hat Enterprise Linux 9     cpe:/o:redhat:enterprise_linux:9
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Red Hat Red Hat OpenShift Container Platform 4     cpe:/a:redhat:openshift:4
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Date Public
2026-04-29 00:00
Credits
Red Hat would like to thank Joshua Rogers (AISLE Research Team) for reporting this issue.
Show details on NVD website
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.