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Fencer Vulns
medium 5.3

CVE-2026-42769 json

Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate

published 2026-06-09 5 mo ago modified 2026-08-13 2 mo ago also EUVD-2026-35486 , GHSA-rpj2-p5pj-r33v , JLSEC-2026-1141

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

Issue Summary: An error in the callback used to verify the certificate provided in a Root CA key update Certificate Management Protocol (CMP) message response rendered the certificate validation ineffectual, which could lead to escalation of credentials from the Registration Authority (RA) level to the root Certification Authority (root CA) level.

Impact Summary: The Registration Autority could replace the root CA certificate for the CMP clients with an arbitrary root CA certificate.

One of the parts of the Certificate Management Protocol (CMP), specified in RFC 9810, is Root Certification Authority (root CA) key Rollover, which is sent by the server in a message with type 'id-it-rootCaKeyUpdate'. As part of these messages, 'newWithOld' certificate, the new root CA certificate signed with the old root CA key, is provided, and verifying its signature is crucial for transferring the trust from the old CA key to the new one.

The 'id-it-rootCaKeyUpdate' messages are expected to be processed with OSSL_CMP_get1_rootCaKeyUpdate(), that is expected to verify the 'newWithOld' certificate. A typo in the certificate chain building code led to adding an incorrect certificate ('newWithOld' instead of 'oldRoot') to the certificate chain, rendering the certificate verification process ineffectual (only the issuer name and the algorithm OIDs were verified by other parts of the verification code).

An attacker who already has credentials that satisfy the CMP message protection checks can generate a new key pair and use a crafted self-signed certificate in its 'id-it-rootCaKeyUpdate' CMP messages which affected CMP clients would accept as a new trust anchor.

Significant preconditions for the attack (having valid RA-level credentials) are the reason the issue was assigned Low severity.

The FIPS modules 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 3.4.6, 3.5.7, 3.6.3, 4.0.1
  • openssl Debian 13 3.5.6-1~deb13u2
  • openssl Debian 14 3.6.3-1

debian advisories DEBIAN-CVE-2026-42769

  • openssl Ubuntu 25.10 3.5.3-1ubuntu3.4
  • openssl Ubuntu 26.04 LTS 3.5.5-1ubuntu3.2

ubuntu advisories UBUNTU-CVE-2026-42769

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-3 SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 3.5.0-160000.8.1

suse advisories SUSE-SU-2026:2648-1SUSE-SU-2026:22251-1SUSE-SU-2026:22315-1

  • 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 3.24, Alpine 3.23, Alpine 3.22 3.5.7-r0

alpine advisories ALPINE-CVE-2026-42769

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

  • openssl Azure Linux 3.0 3.3.7-4

azure linux advisories AZL-92840

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-2026-42769 updated cvss 5.9

openssl: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate

  • 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 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 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
    +2 more products
    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

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia AppBundler
>=1.0.0, <1.0.1
1.0.1
julia OpenSSL_jll
>=3.5.0+0, <3.5.7+0
3.5.7+0
julia Openresty_jll
>=1.29.203+0
 no fix listed

Affected products

  • OpenSSL OpenSSL

Classification

Weakness
  • CWE-295 Improper Certificate Validation
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.