CVE-2026-28390
CWE-476Published: April 7, 2026· Updated: Apr 10, 2026
Official Description
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.
Technical Analysis
CVE-2026-28390 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
News & Research Mentioning CVE-2026-28390
View CSAF Summary SIMATIC CN 4100 contains multiple vulnerabilities which could potentially lead to a compromise in availability, integrity and confidentiality. Siemens has released a new version for SIMATIC CN 4100 and recommends to update to the latest version. The following versions of Siemens SIMATIC are affected: SIMATIC CN 4100 vers:intdot/ hpo_dp_link_enc before using it [WHAT & HOW] Functions dp_enable_link_phy and dp_disable_link_phy can pass link_res without initializing hpo_dp_link_enc and it is necessary to check for null before dereferencing. This fixes 2 FORWARD_NULL issues reported by Coverity. View CVE Details Affected Products Siemens SIMATIC Vendor: Siemens Product Version: SIMATIC CN 4100 Product Status: known_affected Remediations [xlite_meta score:79 src:CISA Alerts xlite_fp:24398be83460e8bd8b0800e5360a3f73a2eb239b4cfc4a9afb9694e799548978]
All References (6)
Quick Facts
Known Threat Actors
Related CVEs (CWE-476)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-28390 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts