NVD / CVE Program· CNA openssl

CVE-2026-42769: Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate

Noroxi assessment

Priority: Monitor (action score 21/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.54% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: OpenSSL OpenSSL 3.4.6, 3.5.7, 3.6.3; azl3 openssl 3.3.7-3 on Azure Linux 3.0 3.3.7-4.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to OpenSSL OpenSSL 3.4.6, 3.5.7, 3.6.3; azl3 openssl 3.3.7-3 on Azure Linux 3.0 3.3.7-4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.3 · v3.1—No exploit Fix available

Weak crypto

Published: Jun 9, 2026
Updated: Jul 23, 2026
EPSS: 0.5% · 45th percentile
CWE: CWE-295

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 21 / 40 · 5.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.5%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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Noroxi analysis

What does it mean in your environment?

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
openssl	openssl	cpe:2.3:a:openssl:openssl

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

openssl openssl3.4.0 and later · before 3.4.6
openssl openssl3.5.0 and later · before 3.5.7
openssl openssl3.6.0 and later · before 3.6.3
openssl openssl4.0.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (openssl). Independent of NVD's CPE analysis and usually ahead of it.

OpenSSL OpenSSL
- 4.0.0 and later · before 4.0.1affected · semver
- 3.6.0 and later · before 3.6.3affected · semver
- 3.5.0 and later · before 3.5.7affected · semver
- 3.4.0 and later · before 3.4.6affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
AlmaLinux:10	openssl	before 1:3.5.5-4.el10_2.alma.1	1:3.5.5-4.el10_2.alma.1
AlmaLinux:10	openssl-devel	before 1:3.5.5-4.el10_2.alma.1	1:3.5.5-4.el10_2.alma.1
AlmaLinux:10	openssl-libs	before 1:3.5.5-4.el10_2.alma.1	1:3.5.5-4.el10_2.alma.1
AlmaLinux:10	openssl-perl	before 1:3.5.5-4.el10_2.alma.1	1:3.5.5-4.el10_2.alma.1
AlmaLinux:9	openssl	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
AlmaLinux:9	openssl-devel	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
AlmaLinux:9	openssl-libs	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
AlmaLinux:9	openssl-perl	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
Alpine:v3.22	openssl	from 3.4.0 · before 3.5.7-r0	3.5.7-r0
Debian:13	openssl	before 3.5.6-1~deb13u2	3.5.6-1~deb13u2
Debian:14	openssl	before 3.6.3-1	3.6.3-1
openSUSE:Leap 16.0	openssl-3	before 3.5.0-160000.8.1	3.5.0-160000.8.1
openSUSE:Tumbleweed	openssl-3	before 3.5.3-6.1	3.5.3-6.1
Red Hat:enterprise_linux:10.2	openssl	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-debuginfo	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-debugsource	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-devel	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-libs	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-libs-debuginfo	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2	openssl-perl	before 1:3.5.5-4.el10_2	1:3.5.5-4.el10_2
Red Hat:enterprise_linux:9::appstream	openssl-debuginfo	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
Red Hat:enterprise_linux:9::appstream	openssl-debugsource	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
Red Hat:enterprise_linux:9::appstream	openssl-devel	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8
Red Hat:enterprise_linux:9::appstream	openssl-libs-debuginfo	before 1:3.5.5-4.el9_8	1:3.5.5-4.el9_8

+77

Same product

openssl: all records

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Published before and after this one in the same product

← EarlierCVE-2026-42767Jun 9, 2026 · NULL Pointer Dereference in CRMF EncryptedValue Decryption
23Monitor
← EarlierCVE-2026-42768Jun 9, 2026 · Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
14Monitor
Later →CVE-2026-42770Jun 9, 2026 · FFC-DH Peer Validation Uses Attacker-Supplied q
14Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
OpenSSL OpenSSL	3.4.6	Vendor (CNA)
OpenSSL OpenSSL	3.5.7	Vendor (CNA)
OpenSSL OpenSSL	3.6.3	Vendor (CNA)
OpenSSL OpenSSL	4.0.1	Vendor (CNA)
azl3 openssl 3.3.7-3 on Azure Linux 3.0	3.3.7-4 · CBL-Mariner Releases	Microsoft (MSRC)
almalinux:openssl	1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-devel	1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-libs	1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
almalinux:openssl-perl	1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10	Package registry (OSV)
alpine:openssl	3.5.7-r0 · Alpine:v3.22	Package registry (OSV)
debian:openssl	3.5.6-1~deb13u2 · Debian:13	Package registry (OSV)
opensuse:openssl-3	3.5.3-6.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:chunkah	0:0.6.0-3.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:openssl	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-debuginfo	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-debugsource	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-devel	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-libs	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-libs-debuginfo	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl-perl	1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2	Package registry (OSV)
red hat:openssl3	0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:openssl3-devel	0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:python-cryptography	0:50.0.0-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:python3-cryptography	0:50.0.0-1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
rocky linux:openssl	1:3.5.5-4.el10_2 · Rocky Linux:10	Package registry (OSV)
suse:openssl-3	3.5.0-160000.8.1 · SUSE:Linux Micro 6.2	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Bob Beckremediation developer
Alex Gaynor (Anthropic)reporter

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2025-4575383 days apartThe x509 application adds trusted use instead of rejected use
26Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0355 · Jun 10, 2026(OpenSSL Güvenlik Zafiyeti)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: high · data can be read
Integrity: none
Availability: none

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: None
Availability impact: None

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

nvd-secondary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

Fix✗ → ✓Sep 28, 2026, 10:09 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/openssl/openssl/commit/54d0989997e5fc26057009a9782c3441ce3842fb

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records