Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-28390 is a high-severity NULL Pointer Dereference (CWE-476) vulnerability in Openssl Openssl. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-28390 is a NULL pointer dereference vulnerability in OpenSSL during the processing of a crafted CMS EnvelopedData message that uses KeyTransportRecipientInfo with RSA-OAEP encryption. The issue occurs because the optional parameters field of the RSA-OAEP SourceFunc algorithm identifier is examined without first checking for its presence, leading to the dereference. Applications and services that call CMS_decrypt() on untrusted input, such as those handling S/MIME processing or CMS-based protocols, are affected. OpenSSL FIPS modules in versions 3.6, 3.5, 3.4, 3.3, and 3.0 are not vulnerable, as the affected code lies outside the FIPS module boundary.
A remote attacker with network access and no privileges required can exploit this vulnerability by supplying a malicious CMS EnvelopedData message to a vulnerable application. Successful exploitation triggers a crash before any authentication or cryptographic operations complete, resulting in a denial of service. The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and is associated with CWE-476 (NULL Pointer Dereference).
Mitigation is available through patches in OpenSSL, as detailed in the following upstream commit references: https://github.com/openssl/openssl/commit/01194a8f1941115cd0383bfa91c736dd3993c8bc, https://github.com/openssl/openssl/commit/2e39b7a6993be445fddb9fbce316fa756e0397b6, https://github.com/openssl/openssl/commit/af2a5fecd3e71a29e7568f9c1453dec5cebbaff4, https://github.com/openssl/openssl/commit/ea7b4ea4f9f853521ba34830cbcadc970d2e0788, and https://github.com/openssl/openssl/commit/fd2f1a6cf53b9ceeca723a001aa4b825d7c7ee75. Security practitioners should update to a patched version of OpenSSL and review applications for exposure to untrusted CMS data.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-19966
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (including static analysis) directly finds null-dereference bugs before deployment.
Documented development standards and tools can enforce null-safety rules and safe pointer usage.
Engineering principles can mandate defensive coding such as explicit null checks before dereference.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices (static analysis, code review, safe coding standards) directly prevent NULL dereference bugs during development.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.