CVE-2026-42767 Details
Description
Issue summary: An attacker-controlled CMP (Certificate Management Protocol) server could trigger a NULL pointer dereference in a CMP client application. Impact summary: A NULL pointer dereference causes a crash of the application and a Denial of Service. An attacker controlling a CMP server (or acting as a man-in-the-middle) could craft a CMP response containing a CRMF (Certificate Request Message Format) CertRepMessage with an EncryptedValue structure where the symmAlg field has an algorithm OID but no parameters field. When the OpenSSL CMP client processes this response, the NULL dereference occurs, causing a crash of the CMP client. Applications that process untrusted CMP/CRMF 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.
A NULL pointer dereference vulnerability has been identified in OpenSSL's CMP client application. This issue arises when the client processes a response from an attacker-controlled CMP server that includes a CRMF CertRepMessage with an EncryptedValue structure. If the symmAlg field contains an algorithm OID without accompanying parameters, the CMP client will dereference a NULL pointer, leading to a crash and causing a denial-of-service condition. This vulnerability affects OpenSSL versions 4.0, 3.6, 3.5, 3.4, and 3.0, but not the FIPS modules in these versions, as the issue occurs outside the FIPS module boundary.
Users of OpenSSL 4.0 should upgrade to OpenSSL 4.0.1. Users of OpenSSL 3.6 should upgrade to OpenSSL 3.6.3. Users of OpenSSL 3.5 should upgrade to OpenSSL 3.5.7. Users of OpenSSL 3.4 should upgrade to OpenSSL 3.4.6. Users of OpenSSL 3.0 should upgrade to OpenSSL 3.0.21.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 9, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-476 | NULL Pointer Dereference | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openssl openssl | >= 3.0.0, < 3.0.21 >= 3.4.0, < 3.4.6 >= 3.5.0, < 3.5.7 >= 3.6.0, < 3.6.3 4.0.0 - |
CPE
Remediation
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Change History
7 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 16, 2026 | Initial Analysis | [email protected] |
| Jun 10, 2026 | CVE Modified | [email protected] |
| Jun 9, 2026 | CVE Modified | CISA-ADP |
| Jun 9, 2026 | New CVE Received | [email protected] |