CVE-2026-42769

Publication date 9 June 2026

Last updated 18 June 2026

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

5.3 · Medium

Score breakdown

Description

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.

Read the notes from the security team

Why is this CVE low priority?

OpenSSL developers have rated this as being low severity

Learn more about Ubuntu priority

Status

Package Ubuntu Release Status
edk2 26.04 LTS resolute
Needs evaluation
25.10 questing
Needs evaluation
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
nodejs 26.04 LTS resolute
Not affected
25.10 questing
Not affected
24.04 LTS noble
Not affected
22.04 LTS jammy
Vulnerable
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
14.04 LTS trusty
Not affected
openssl 26.04 LTS resolute
Fixed 3.5.5-1ubuntu3.2
25.10 questing
Fixed 3.5.3-1ubuntu3.4
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
openssl-fips 26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble
Not affected
22.04 LTS jammy
Not affected
openssl1.0 26.04 LTS resolute Not in release
25.10 questing Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Not affected

Notes

mdeslaur

edk2 in jammy embeds OpenSSL 1.1.1j edk2 in noble embeds OpenSSL 3.0.9 edk2 in plucky embeds OpenSSL 3.4.0 edk2 in questing embeds OpenSSL 3.4.0 nodejs in jammy embeds OpenSSL 1.1.1m OpenSSL 4.0, 3.6, 3.5, and 3.4 are vulnerable to this issue.

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.3 · Medium

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

References

Related Ubuntu Security Notices (USN)

Other references

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