OpenSSL CMS NULL Deref via KeyTransportRecipientInfo before 3.6
CVE-2026-28390 Published on April 7, 2026
Possible NULL Dereference When Processing CMS KeyTransportRecipientInfo
Issue summary: During processing of a crafted CMS EnvelopedData message
with KeyTransportRecipientInfo a NULL pointer dereference can happen.
Impact summary: Applications that process attacker-controlled CMS data may
crash before authentication or cryptographic operations occur resulting in
Denial of Service.
When a CMS EnvelopedData message that uses KeyTransportRecipientInfo with
RSA-OAEP encryption is processed, the optional parameters field of
RSA-OAEP SourceFunc algorithm identifier is examined without checking
for its presence. This results in a NULL pointer dereference if the field
is missing.
Applications and services that call CMS_decrypt() on untrusted input
(e.g., S/MIME processing or CMS-based protocols) are vulnerable.
The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this
issue, as the affected code is outside the OpenSSL FIPS module boundary.
Weakness Type
NULL Pointer Dereference
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions.
Products Associated with CVE-2026-28390
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Affected Versions
OpenSSL:- Version 3.6.0 and below 3.6.2 is affected.
- Version 3.5.0 and below 3.5.6 is affected.
- Version 3.4.0 and below 3.4.5 is affected.
- Version 3.3.0 and below 3.3.7 is affected.
- Version 3.0.0 and below 3.0.20 is affected.
- Version 1.1.1 and below 1.1.1zg is affected.
- Version 1.0.2 and below 1.0.2zp is affected.