CVE-2026-42767

Summary

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.

Affected Software

VendorProductVersion RangeStatus
OpenSSLOpenSSL4.0.0 < 4.0.1affected
OpenSSLOpenSSL3.6.0 < 3.6.3affected
OpenSSLOpenSSL3.5.0 < 3.5.7affected
OpenSSLOpenSSL3.4.0 < 3.4.6affected
OpenSSLOpenSSL3.0.0 < 3.0.21affected

Weaknesses

  • CWE-476: CWE-476 NULL Pointer Dereference

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References