Heap-based buffer overflow in OpenSSL - CVE-2026-7383

Vulnerability identifier: #VU134276

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-7383

CWE-ID: CWE-122

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to execute arbitrary code.

The vulnerability exists due to heap-based buffer overflow in ASN1_mbstring_copy() and ASN1_mbstring_ncopy() when converting attacker-controlled multibyte strings to Unicode output. A local user can supply extremely large crafted input to execute arbitrary code.

Triggering the issue requires direct use of ASN1_mbstring_copy() or ASN1_mbstring_ncopy(), or a custom string type registered via ASN1_STRING_TABLE_add(), with attacker-controlled input on the order of half a gigabyte or more.

OpenSSL
Debian Linux
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 12 SP5
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
IBM i
Fedora
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for x86_64
FreeBSD
Ubuntu
Basesystem Module
Development Tools Module
Legacy Module
openSUSE Leap
openEuler
Anolis OS
IBM Cloud Pak for Data System
IBM MQ Operator
LANTIME Operating System Firmware (LTOS)
IBM supplied MQ Advanced container images
Operator for PostgreSQL
openssl (Ubuntu package)
openssl-1_0_0-debuginfo
libopenssl1_0_0-hmac
libopenssl-1_0_0-devel
openssl-1_0_0-debugsource
openssl-1_0_0
libopenssl1_0_0-debuginfo
libopenssl1_0_0
openssl-1_0_0-doc
libopenssl1_0_0-debuginfo-32bit
libopenssl-1_0_0-devel-32bit
libopenssl1_0_0-hmac-32bit
libopenssl1_0_0-32bit
libopenssl10
libopenssl10-debuginfo
openssl-1_1-debugsource
libopenssl1_1-debuginfo
libopenssl1_1
libopenssl-1_1-devel
libopenssl-1_1-devel-32bit
libopenssl1_1-hmac-32bit
libopenssl1_1-debuginfo-32bit
libopenssl1_1-32bit
openssl-1_1-debuginfo
openssl-1_1
libopenssl1_1-hmac
openssl
openssl-debuginfo
openssl-debugsource
openssl-devel
openssl-libs
openssl-help
libopenssl1_1-hmac-64bit
libopenssl-1_1-devel-64bit
openssl-1_1-doc
libopenssl1_1-32bit-debuginfo
libopenssl1_1-64bit
libopenssl1_1-64bit-debuginfo
compat-openssl11-debuginfo
compat-openssl11-devel
compat-openssl11-libs
compat-openssl11
compat-openssl11-debugsource
openssl-perl
openssl-3-debugsource
openssl-3-debuginfo
libopenssl3
openssl-3
libopenssl-3-devel
libopenssl3-debuginfo
libopenssl3-32bit
libopenssl-3-devel-32bit
libopenssl3-32bit-debuginfo
libopenssl3-64bit-debuginfo
libopenssl3-64bit
libopenssl-3-devel-64bit
openssl-3-doc
openssl-doc
openssl (Debian package)
libopenssl-3-fips-provider-32bit-debuginfo
libopenssl-3-fips-provider
libopenssl-3-fips-provider-debuginfo
libopenssl-3-fips-provider-32bit
libopenssl-3-fips-provider-64bit
libopenssl-3-fips-provider-64bit-debuginfo
openssl (Red Hat package)
openssl3
shim-debugsource
shim-signed
shim-debuginfo
shim
edk2-devel
python3-edk2-devel
edk2-ovmf
edk2-help
edk2
edk2-debuginfo
edk2-debugsource
edk2-aarch64
EntireX

Install security update from vendor's website.

OpenSSL - addressed in versions 1.0.2zq, 1.1.1zh, 3.0.21, 3.4.6, 3.5.7, 3.6.3, 4.0.1
IBM Cloud Pak for Data System - update to 8.10.26.07.SP3
IBM MQ Operator - addressed in versions 3.2.26 SC2, 4.0.1 SC2
LANTIME Operating System Firmware (LTOS) - update to 7.10.013
IBM supplied MQ Advanced container images - update to 10.0.0.0-r2
openssl (Ubuntu package) - addressed in versions 1.0.1f-1ubuntu2.27+esm14, 1.0.2g-1ubuntu4.20+esm16, 1.0.2n-1ubuntu5.13+esm5, 1.1.1f-1ubuntu2.24+esm4, 1.1.1-1ubuntu2.1~18.04.23+esm9, 3.0.2-0ubuntu1.25, 3.0.13-0ubuntu3.11, 3.5.3-1ubuntu3.4, 3.5.5-1ubuntu3.2
openssl-1_0_0-debuginfo - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
libopenssl1_0_0-hmac - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
libopenssl-1_0_0-devel - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
openssl-1_0_0-debugsource - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
openssl-1_0_0 - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
libopenssl1_0_0-debuginfo - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
libopenssl1_0_0 - addressed in versions 1.0.2p-3.109.1, 1.0.2p-150000.3.108.1
openssl-1_0_0-doc - update to 1.0.2p-3.109.1
libopenssl1_0_0-debuginfo-32bit - update to 1.0.2p-3.109.1
libopenssl-1_0_0-devel-32bit - update to 1.0.2p-3.109.1
libopenssl1_0_0-hmac-32bit - update to 1.0.2p-3.109.1
libopenssl1_0_0-32bit - update to 1.0.2p-3.109.1
libopenssl10 - update to 1.0.2p-150000.3.108.1
libopenssl10-debuginfo - update to 1.0.2p-150000.3.108.1
openssl-1_1-debugsource - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl1_1-debuginfo - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl1_1 - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl-1_1-devel - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl-1_1-devel-32bit - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1
libopenssl1_1-hmac-32bit - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2
libopenssl1_1-debuginfo-32bit - update to 1.1.1d-2.131.1
libopenssl1_1-32bit - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
openssl-1_1-debuginfo - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
openssl-1_1 - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl1_1-hmac - addressed in versions 1.1.1d-2.131.1, 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2
openssl - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
openssl-debuginfo - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
openssl-debugsource - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
openssl-devel - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
openssl-libs - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
openssl-help - addressed in versions 1.1.1f-43, 1.1.1wa-17, 3.0.12-52
libopenssl1_1-hmac-64bit - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2
libopenssl-1_1-devel-64bit - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1
openssl-1_1-doc - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1
libopenssl1_1-32bit-debuginfo - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1, 1.1.1w-150700.11.22.1
libopenssl1_1-64bit - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1
libopenssl1_1-64bit-debuginfo - addressed in versions 1.1.1l-150400.7.96.2, 1.1.1l-150500.17.57.2, 1.1.1w-150600.5.32.1
compat-openssl11-debuginfo - update to 1.1.1m-19
compat-openssl11-devel - update to 1.1.1m-19
compat-openssl11-libs - update to 1.1.1m-19
compat-openssl11 - update to 1.1.1m-19
compat-openssl11-debugsource - update to 1.1.1m-19
openssl-perl - addressed in versions 1.1.1wa-17, 3.0.12-52
openssl-3-debugsource - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
openssl-3-debuginfo - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl3 - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
openssl-3 - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-devel - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl3-debuginfo - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl3-32bit - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-devel-32bit - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1
libopenssl3-32bit-debuginfo - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl3-64bit-debuginfo - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1
libopenssl3-64bit - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1
libopenssl-3-devel-64bit - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1
openssl-3-doc - addressed in versions 3.0.8-150400.4.87.1, 3.0.8-150500.5.66.1, 3.1.4-150600.5.53.1
openssl-doc - update to 3.0.12-26
openssl-perl - update to 3.0.12-26
openssl-libs - update to 3.0.12-26
openssl-devel - update to 3.0.12-26
openssl - update to 3.0.12-26
openssl (Debian package) - addressed in versions 3.0.20-1~deb12u2, 3.5.6-1~deb13u2
libopenssl-3-fips-provider-32bit-debuginfo - addressed in versions 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-fips-provider - addressed in versions 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-fips-provider-debuginfo - addressed in versions 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-fips-provider-32bit - addressed in versions 3.1.4-150600.5.53.1, 3.2.3-150700.5.36.1
libopenssl-3-fips-provider-64bit - update to 3.1.4-150600.5.53.1
libopenssl-3-fips-provider-64bit-debuginfo - update to 3.1.4-150600.5.53.1
openssl (Red Hat package) - addressed in versions 3.5.5-4.el9_8, 3.5.5-4.el10_2
openssl3 - update to 3.5.5-5.el8
openssl - update to 3.5.7-1.fc44
EntireX - update to 11.1 Fix6
shim-debugsource - update to 15.7-27
shim-signed - update to 15.7-27
shim-debuginfo - update to 15.7-27
shim - update to 15.7-27
edk2-devel - addressed in versions 202308-37, 202308-41
python3-edk2-devel - addressed in versions 202308-37, 202308-41
edk2-ovmf - addressed in versions 202308-37, 202308-41
edk2-help - addressed in versions 202308-37, 202308-41
edk2 - addressed in versions 202308-37, 202308-41
edk2-debuginfo - addressed in versions 202308-37, 202308-41
edk2-debugsource - addressed in versions 202308-37, 202308-41
edk2-aarch64 - addressed in versions 202308-37, 202308-41

• https://openssl-library.org/news/secadv/20260609.txt

• Multiple vulnerabilities in OpenSSL
• Debian update for openssl
• Ubuntu update for openssl
• Ubuntu update for openssl
• Fedora 44 update for openssl
• Red Hat Enterprise Linux 10 update for openssl
• Red Hat Enterprise Linux 9 update for openssl
• FreeBSd update for OpenSSL
• SUSE update for openssl-1_1
• SUSE update for openssl-3
• SUSE update for openssl-1_0_0
• SUSE update for openssl-3
• SUSE update for openssl-1_0_0
• SUSE update for openssl-1_1
• SUSE update for openssl-1_1
• SUSE update for openssl-1_1
• SUSE update for openssl-3
• openEuler 22.03 LTS SP4 update for openssl
• openEuler 20.03 LTS SP4 update for openssl
• openEuler 24.03 LTS SP3 update for openssl
• openEuler 24.03 LTS SP1 update for openssl
• openEuler 24.03 LTS SP3 update for edk2
• openEuler 24.03 LTS SP1 update for edk2
• openEuler update for shim
• openEuler 24.03 LTS SP3 update for compat-openssl11
• openEuler 24.03 LTS SP1 update for compat-openssl11
• SUSE update for openssl-1_1
• Anolis OS update for openssl
• SUSE update for openssl-3
• Multiple vulnerabilities in IBM Operator for PostgreSQL
• Multiple vulnerabilities in IBM EntireX
• Multiple vulnerabilities in IBM MQ Operator and Queue manager container images
• Multiple vulnerabilities in IBM i
• Fedora EPEL 8 update for openssl3
• Multiple vulnerabilities in Meinberg LANTIME firmware
• Multiple vulnerabilities in IBM Cloud Pak for Data System