CVE-2026-28389
Possible NULL Dereference When Processing CMS KeyAgreeRecipientInfo
Description
Issue summary: During processing of a crafted CMS EnvelopedData message with KeyAgreeRecipientInfo 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 KeyAgreeRecipientInfo is processed, the optional parameters field of KeyEncryptionAlgorithmIdentifier 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.
INFO
Published Date :
April 7, 2026, 10:16 p.m.
Last Modified :
April 7, 2026, 10:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Update to a version of the software that addresses this issue.
- Avoid processing untrusted CMS data with affected functions.
- Implement checks for optional parameters before dereferencing.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-28389.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-28389 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-28389
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-28389 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-28389 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Apr. 07, 2026
Action Type Old Value New Value Added Description Issue summary: During processing of a crafted CMS EnvelopedData message with KeyAgreeRecipientInfo 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 KeyAgreeRecipientInfo is processed, the optional parameters field of KeyEncryptionAlgorithmIdentifier 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. Added CWE CWE-476 Added Reference https://github.com/openssl/openssl/commit/16cea4188e0ea567deb4f93f85902247e67384f5 Added Reference https://github.com/openssl/openssl/commit/785cbf7ea3b5a6f5adf0c1ccb92b79d89c35c616 Added Reference https://github.com/openssl/openssl/commit/7b5274e812400cacb6f3be4c2df5340923fa807f Added Reference https://github.com/openssl/openssl/commit/c6725634e089eb2b634b10ede33944be7248172a Added Reference https://github.com/openssl/openssl/commit/f80f83bc5fd036bc47d773e8b15a001e2b4ce686 Added Reference https://openssl-library.org/news/secadv/20260407.txt