Input validation error in OpenSSL - CVE-2026-42770

Vulnerability identifier: #VU134285

CSH Severity: Medium

CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-42770

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to recover the victim's private key.

The vulnerability exists due to improper input validation in EVP_PKEY_derive_set_peer() when validating a DHX (X9.42) peer key using the peer-supplied q parameter for subgroup membership checks. A remote attacker can present a forged DHX peer key to recover the victim's private key.

The realistic attack surface is narrow and is principally limited to deployments using long-lived X9.42 DHX static keys with interactive protocols.

OpenSSL
SUSE Linux Enterprise Server 15 SP6
Debian Linux
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Micro for Rancher
SUSE Linux Enterprise Micro
Fedora
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
FreeBSD
Basesystem Module
openSUSE Leap
Ubuntu
Anolis OS
openEuler
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)
libopenssl3-64bit
libopenssl3-32bit
libopenssl3-debuginfo
libopenssl-3-devel
openssl-3
libopenssl3
openssl-3-debuginfo
openssl-3-debugsource
libopenssl-3-devel-32bit
libopenssl3-32bit-debuginfo
libopenssl3-64bit-debuginfo
libopenssl-3-devel-64bit
openssl-3-doc
openssl-doc
openssl
openssl-devel
openssl-libs
openssl-perl
openssl-debugsource
openssl-debuginfo
openssl-help
openssl (Debian package)
libopenssl-3-fips-provider
libopenssl-3-fips-provider-debuginfo
libopenssl-3-fips-provider-32bit-debuginfo
libopenssl-3-fips-provider-32bit
libopenssl-3-fips-provider-64bit
libopenssl-3-fips-provider-64bit-debuginfo
openssl (Red Hat package)
openssl3
edk2-debugsource
python3-edk2-devel
edk2-ovmf
edk2-help
edk2-aarch64
edk2-devel
edk2-debuginfo
edk2
EntireX

Install security update from vendor's website.

OpenSSL - addressed in versions 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 3.0.2-0ubuntu1.25, 3.0.13-0ubuntu3.11, 3.5.3-1ubuntu3.4, 3.5.5-1ubuntu3.2
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
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
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
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
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
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-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
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
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
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 - update to 3.0.12-26
openssl-devel - update to 3.0.12-26
openssl-libs - update to 3.0.12-26
openssl-perl - update to 3.0.12-26
openssl-perl - update to 3.0.12-52
openssl-libs - update to 3.0.12-52
openssl-devel - update to 3.0.12-52
openssl-debugsource - update to 3.0.12-52
openssl-debuginfo - update to 3.0.12-52
openssl - update to 3.0.12-52
openssl-help - update to 3.0.12-52
openssl (Debian package) - addressed in versions 3.0.20-1~deb12u2, 3.5.6-1~deb13u2
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-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
edk2-debugsource - addressed in versions 202308-41, 202308-43
python3-edk2-devel - addressed in versions 202308-41, 202308-43
edk2-ovmf - addressed in versions 202308-41, 202308-43
edk2-help - addressed in versions 202308-41, 202308-43
edk2-aarch64 - addressed in versions 202308-41, 202308-43
edk2-devel - addressed in versions 202308-41, 202308-43
edk2-debuginfo - addressed in versions 202308-41, 202308-43
edk2 - update to 202308-41

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

• Multiple vulnerabilities in OpenSSL
• Debian 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-3
• SUSE update for openssl-3
• SUSE update for openssl-3
• openEuler 24.03 LTS SP3 update for openssl
• openEuler 24.03 LTS SP1 update for openssl
• 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
• openEuler 24.03 LTS SP3 update for edk2
• openEuler 24.03 LTS SP1 update for edk2
• Fedora EPEL 8 update for openssl3
• Multiple vulnerabilities in Meinberg LANTIME firmware
• Multiple vulnerabilities in IBM Cloud Pak for Data System