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Fencer Vulns
medium 5.9

CVE-2026-42766 json

Possible NULL Dereference in Password-Based CMS Decryption

published 2026-06-09 5 mo ago modified 2026-08-13 2 mo ago also EUVD-2026-35483 , GHSA-58mv-qqmv-gqgv , JLSEC-2026-1138

cvss
5.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 64%
public exploits
0
none known

Summary

Issue summary: A specially crafted password-encrypted CMS message can trigger a NULL pointer dereference during CMS decryption.

Impact summary: This NULL pointer dereference leads to an application crash and a Denial of Service.

The CMS PasswordRecipientInfo.keyDerivationAlgorithm field is defined as OPTIONAL in the ASN.1 specification and may therefore be absent in specially crafted inputs. During the password-based CMS decryption the OpenSSL CMS implementation dereferences this field without first checking whether it was present.

An attacker who supplies such a CMS message to an application performing password-based CMS decryption can trigger an application crash, leading to a Denial of Service.

Applications that process password-encrypted CMS messages may be affected.

The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this issue, as the affected code is outside the OpenSSL FIPS module boundary.

Patch / fix

  • julia AppBundler 1.0.1
  • julia OpenSSL_jll 3.5.7+0
  • OpenSSL OpenSSL 1.0.2zq, 1.1.1zh, 3.0.21, 3.4.6, 3.5.7, 3.6.3, 4.0.1
  • openssl Debian 12 3.0.20-1~deb12u2
  • openssl Debian 13 3.5.6-1~deb13u2
  • openssl Debian 14 3.6.3-1

debian advisories DEBIAN-CVE-2026-42766

  • openssl Ubuntu 22.04 LTS 3.0.2-0ubuntu1.25
  • openssl Ubuntu 24.04 LTS 3.0.13-0ubuntu3.11
  • openssl Ubuntu 25.10 3.5.3-1ubuntu3.4
  • openssl Ubuntu 26.04 LTS 3.5.5-1ubuntu3.2
  • openssl Ubuntu Pro 14.04 LTS 1.0.1f-1ubuntu2.27+esm14
  • openssl Ubuntu Pro 16.04 LTS 1.0.2g-1ubuntu4.20+esm16
  • openssl Ubuntu Pro 18.04 LTS 1.1.1-1ubuntu2.1~18.04.23+esm9
  • openssl Ubuntu Pro FIPS-updates 18.04 LTS 1.1.1-1ubuntu2.fips.2.1~18.04.23.9

ubuntu advisories UBUNTU-CVE-2026-42766

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • bootupd hummingbird 1 0.3.2-1.hum1
  • rust-bootupd hummingbird 1 0.3.2-1.hum1
  • ruby3.4 hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-libs hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-bundled-gems hummingbird 1 3.4.10-31.7.hum1
  • ruby3.4-default-gems hummingbird 1 3.4.10-31.7.hum1
  • ruby4.0 hummingbird 1 4.0.6-37.3.hum1
  • ruby4.0-libs hummingbird 1 4.0.6-37.3.hum1

red hat advisories RHSA-2026:67551RHSA-2026:62790RHSA-2026:62563RHSA-2026:62562RHSA-2026:55543RHSA-2026:42825

  • openssl-3 SLE Module for Basesystem 15 SP7 3.2.3-150700.5.36.1
  • openssl-1_1 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 1.1.1l-150400.7.96.2
  • openssl-3 SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 3.0.8-150400.4.87.1
  • openssl-3 SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 3.5.0-160000.8.1
  • openssl-1_1 SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 1.1.1l-150500.17.57.2
  • openssl-1_0_0 SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +6 more 1.0.2p-150000.3.108.1
  • openssl-3 SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 3.0.8-150500.5.66.1
  • openssl-1_1 SLE Module for Legacy 15 SP7, SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 1.1.1w-150700.11.22.1

suse advisories SUSE-SU-2026:2648-1SUSE-SU-2026:2614-1SUSE-SU-2026:2598-1SUSE-SU-2026:22251-1SUSE-SU-2026:22315-1SUSE-SU-2026:2405-1

  • openssl-3 openSUSE Leap 16.0 3.5.0-160000.8.1
  • openssl-3 openSUSE Tumbleweed 3.5.3-6.1

opensuse advisories openSUSE-SU-2026:21005-1openSUSE-SU-2026:11023-1

  • openssl AlmaLinux 10 1:3.5.5-4.el10_2.alma.1
  • openssl-libs AlmaLinux 10 1:3.5.5-4.el10_2.alma.1
  • openssl-perl AlmaLinux 10 1:3.5.5-4.el10_2.alma.1
  • openssl AlmaLinux 9 1:3.5.5-4.el9_8
  • openssl-libs AlmaLinux 9 1:3.5.5-4.el9_8
  • openssl-perl AlmaLinux 9 1:3.5.5-4.el9_8

almalinux advisories ALSA-2026:25237ALSA-2026:25239

  • openssl Rocky Linux 10 1:3.5.5-4.el10_2
  • openssl Rocky Linux 9 1:3.5.5-4.el9_8

rocky linux advisories RLSA-2026:25237RLSA-2026:25239

  • openssl Alpine 3.21 3.3.7-r1
  • openssl Alpine 3.24, Alpine 3.23, Alpine 3.22 3.5.7-r0

alpine advisories ALPINE-CVE-2026-42766

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • edk2 Azure Linux 3.0 20240524git3e722403cd16-18
  • openssl Azure Linux 3.0 3.3.7-3

azure linux advisories AZL-89867AZL-89943

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-42766 updated cvss 5.3

openssl: Possible NULL Dereference in Password-Based CMS Decryption

  • Red Hat Enterprise Linux 6 openssl, openssl-perl Red Hat Enterprise Linux 7 ovmf, OVMF, AAVMF Red Hat Enterprise Linux 8 edk2, shim, openssl, shim-x64, edk2-ovmf, shim-aa64, +9 more Red Hat Enterprise Linux 9 edk2, shim, shim-x64, edk2-ovmf, shim-aa64, edk2-tools, +4 more Red Hat Enterprise Linux 10 edk2, shim, shim-unsigned-x64, shim-unsigned-aarch64 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.17 cert-manager/cert-manager-operator-rhel9 1791788287, cert-manager/jetstack-cert-manager-rhel9 1791371069, cert-manager/cert-manager-operator-bundle 1791970484, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791371080
    fixed: vendor fix RHSA-2026:82888
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.18 cert-manager/cert-manager-operator-rhel9 1789029076, cert-manager/jetstack-cert-manager-rhel9 1791459711, cert-manager/cert-manager-istio-csr-rhel9 1791459759, cert-manager/cert-manager-operator-bundle 1791966259, cert-manager/jetstack-cert-manager-acmesolver-rhel9 1791459707
    fixed: vendor fix RHSA-2026:82354
  • Red Hat Cert Manager support for Red Hat OpenShift release 1.20 cert-manager/cert-manager-trust-manager-rhel9 1790598593
    fixed: vendor fix RHSA-2026:72502
  • Red Hat Discovery 2 discovery/discovery-ui-rhel9 1782166952, discovery/discovery-server-rhel9 1782159791
    fixed: vendor fix RHSA-2026:29197
  • Red Hat Enterprise Linux AppStream (v. 9) openssl-perl 3.5.5-4.el9_8
    fixed: vendor fix RHSA-2026:25239
  • Red Hat Enterprise Linux AppStream (v. 10) openssl-perl 3.5.5-4.el10_2
    fixed: vendor fix RHSA-2026:25237
  • Red Hat Enterprise Linux BaseOS (v. 9) openssl 3.5.5-4.el9_8, openssl-libs 3.5.5-4.el9_8
    fixed: vendor fix RHSA-2026:25239
show 5 more
  • Red Hat Enterprise Linux BaseOS (v. 10) openssl 3.5.5-4.el10_2, openssl-libs 3.5.5-4.el10_2
    fixed: vendor fix RHSA-2026:25237
  • Red Hat Hardened Images bootupd 0.3.2-1.hum1, chunkah 0.6.0-3.hum1, openssl 3.5.8-0.1.hum1, openssl3 3.5.8-0.1.hum1, ruby4.0 4.0.6-37.3.hum1, ruby3.3 3.3.10-23.6.hum1, +20 more
    fixed: vendor fix RHSA-2026:67551
  • Red Hat Insights proxy 1.5 insights-proxy/insights-proxy-container-rhel9 1782890503
    fixed: vendor fix RHSA-2026:34102
  • Red Hat Update Infrastructure 5 rhui5/cds-rhel9 1781525684, rhui5/rhua-rhel9 1781525739, rhui5/haproxy-rhel9 1781525671, rhui5/rhua-tp-rhel9 1787241260, rhui5/installer-rhel9 1781525693, rhui5/installer-tp-rhel9 1787135742, +1 more
    fixed: vendor fix RHSA-2026:58981
  • Red Hat Hardened Images rust, unbound, netavark, openshell, rust-podman-sequoia, rubygem3.3-rbs 3.4.0-23.6.hum1, +50 more Red Hat JBoss Core Services jbcs-httpd24-openssl, jbcs-httpd24-openssl-libs, jbcs-httpd24-openssl-perl, jbcs-openssl-win6-x86_64.zip 3.5.5-SP4 Red Hat JBoss Web Server 6 jws-optional-native-components-win6-x86_64.zip 6.2.4.ER1 Red Hat JBoss Web Server 7 jws-optional-native-components-win6-x86_64.zip 6.2.4.ER1 Red Hat Update Infrastructure 5 rhui5/cds-tp-rhel9 1787241206, rhui5/cds-kubernetes-rhel9 1781525677
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

1.06% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
julia AppBundler
>=1.0.0, <1.0.1
1.0.1
julia OpenSSL_jll
<3.5.7+0
3.5.7+0
julia Openresty_jll
all versions
 no fix listed

Affected products

  • OpenSSL OpenSSL

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.