Heap-based buffer overflow in GnuTLS - CVE-2026-33845

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Main Vulnerability Database Vulnerabilities #VU128570

Heap-based buffer overflow in GnuTLS - CVE-2026-33845

Published: April 30, 2026


Vulnerability identifier: #VU128570
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33845
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service or execute arbitrary code.

The vulnerability exists due to a heap-based buffer overflow in the DTLS reassembly code when processing crafted DTLS fragments. A remote attacker can send specially crafted DTLS traffic to cause a denial of service or execute arbitrary code.


Affected software

GnuTLS
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 15 SP6
Debian Linux
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Anolis OS
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Basesystem Module
openSUSE Leap
Ubuntu
openEuler
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
libgnutls28-32bit
libgnutls28-debuginfo-32bit
libgnutls-devel
gnutls-debuginfo
libgnutls-openssl27-debuginfo
libgnutls28
gnutls
gnutls-debugsource
libgnutls-openssl27
libgnutls28-debuginfo
libgnutls-openssl-devel
libgnutlsxx-devel
gnutls (Red Hat package)
gnutls28 (Ubuntu package)
libgnutls30-32bit
libgnutls30
libgnutls30-debuginfo
libgnutls30-debuginfo-32bit
gnutls-c++
gnutls-dane
gnutls-devel
gnutls-utils
libgnutls30-64bit
libgnutls-devel-64bit
libgnutls30-64bit-debuginfo
gnutls-guile
libgnutlsxx28
gnutls-guile-debuginfo
libgnutls30-hmac
libgnutls30-hmac-64bit
libgnutls30-hmac-32bit
libgnutls-devel-32bit
libgnutls30-32bit-debuginfo
libgnutlsxx28-debuginfo
gnutls28 (Debian package)
gnutls-help
libgnutlsxx30-debuginfo
libgnutlsxx30
libtasn1 (Red Hat package)

How to mitigate CVE-2026-33845

Install security update from vendor's website.

GnuTLS - update to 3.8.13
libgnutls28-32bit - update to 3.3.27-3.18.1
libgnutls28-debuginfo-32bit - update to 3.3.27-3.18.1
libgnutls-devel - addressed in versions 3.3.27-3.18.1, 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
gnutls-debuginfo - addressed in versions 3.3.27-3.18.1, 3.7.3-150400.4.59.1, 3.7.3-150400.24.2, 3.8.3-150600.4.20.1
libgnutls-openssl27-debuginfo - update to 3.3.27-3.18.1
libgnutls28 - update to 3.3.27-3.18.1
gnutls - addressed in versions 3.3.27-3.18.1, 3.7.3-150400.4.59.1, 3.7.3-150400.24.2, 3.8.3-150600.4.20.1
gnutls-debugsource - addressed in versions 3.3.27-3.18.1, 3.4.17-8.23.1, 3.7.3-150400.4.59.1, 3.7.3-150400.24.2, 3.8.3-150600.4.20.1
libgnutls-openssl27 - update to 3.3.27-3.18.1
libgnutls28-debuginfo - update to 3.3.27-3.18.1
libgnutls-openssl-devel - update to 3.3.27-3.18.1
libgnutlsxx-devel - addressed in versions 3.3.27-3.18.1, 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
gnutls (Red Hat package) - addressed in versions 3.3.29-9.el7_9.1, 3.6.14-10.el8_4.1, 3.6.16-5.el8_6.5, 3.7.6-21.el9_2.7, 3.8.9-9.el10_0.19
gnutls28 (Ubuntu package) - addressed in versions 3.4.10-4ubuntu1.9+esm3, 3.5.18-1ubuntu1.6+esm3, 3.6.13-2ubuntu1.12+esm2, 3.7.3-4ubuntu1.9, 3.8.3-1.1ubuntu3.6, 3.8.9-3ubuntu2.2, 3.8.12-2ubuntu1.1
libgnutls30-32bit - addressed in versions 3.4.17-8.23.1, 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
libgnutls30 - addressed in versions 3.4.17-8.23.1, 3.7.3-150400.4.59.1, 3.7.3-150400.24.2, 3.8.3-150600.4.20.1
libgnutls30-debuginfo - addressed in versions 3.4.17-8.23.1, 3.7.3-150400.4.59.1, 3.7.3-150400.24.2, 3.8.3-150600.4.20.1
libgnutls30-debuginfo-32bit - update to 3.4.17-8.23.1
gnutls - update to 3.6.16-8.0.2
gnutls-c++ - update to 3.6.16-8.0.2
gnutls-dane - update to 3.6.16-8.0.2
gnutls-devel - update to 3.6.16-8.0.2
gnutls-utils - update to 3.6.16-8.0.2
libgnutls30-64bit - addressed in versions 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
libgnutls-devel-64bit - addressed in versions 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
libgnutls30-64bit-debuginfo - addressed in versions 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
gnutls-guile - update to 3.7.3-150400.4.59.1
libgnutlsxx28 - update to 3.7.3-150400.4.59.1
gnutls-guile-debuginfo - update to 3.7.3-150400.4.59.1
libgnutls30-hmac - addressed in versions 3.7.3-150400.4.59.1, 3.7.3-150400.24.2
libgnutls30-hmac-64bit - update to 3.7.3-150400.4.59.1
libgnutls30-hmac-32bit - update to 3.7.3-150400.4.59.1
libgnutls-devel-32bit - addressed in versions 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
libgnutls30-32bit-debuginfo - addressed in versions 3.7.3-150400.4.59.1, 3.8.3-150600.4.20.1
libgnutlsxx28-debuginfo - update to 3.7.3-150400.4.59.1
gnutls28 (Debian package) - addressed in versions 3.7.9-2+deb12u7, 3.8.9-3+deb13u4
gnutls-dane - update to 3.8.2-12
gnutls - update to 3.8.2-12
gnutls-debuginfo - update to 3.8.2-12
gnutls-debugsource - update to 3.8.2-12
gnutls-devel - update to 3.8.2-12
gnutls-utils - update to 3.8.2-12
gnutls-help - update to 3.8.2-12
libgnutlsxx30-debuginfo - update to 3.8.3-150600.4.20.1
libgnutlsxx30 - update to 3.8.3-150600.4.20.1
libtasn1 (Red Hat package) - addressed in versions 4.13-3.el8_4.1, 4.13-3.el8_6.2

External References

Related Security Bulletins