Vulnerability · Published Apr 7, 2026 · Assigned by openssl
CVE-2026-28389Possible NULL Dereference When Processing CMS KeyAgreeRecipientInfo
High 7.5
In plain English
A high-severity null pointer dereference in OpenSSL from OpenSSL. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 58% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | openssl | 3.3.7-r0 | ALPINE-CVE-2026-28389 |
| Alpine:v3.21 | openssl | 3.3.7-r0 | ALPINE-CVE-2026-28389 |
| Alpine:v3.22 | openssl | 3.5.6-r0 | ALPINE-CVE-2026-28389 |
| Alpine:v3.23 | openssl | 3.5.6-r0 | ALPINE-CVE-2026-28389 |
| Alpine:v3.24 | openssl | 3.5.6-r0 | ALPINE-CVE-2026-28389 |
| Debian:12 | openssl | 3.0.19-1~deb12u2 | DEBIAN-CVE-2026-28389 |
| Debian:13 | openssl | 3.5.5-1~deb13u2 | DEBIAN-CVE-2026-28389 |
| Debian:14 | openssl | 3.6.2-1 | DEBIAN-CVE-2026-28389 |
| Ubuntu:22.04:LTS | edk2 | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:24.04:LTS | edk2 | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:25.10 | edk2 | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.04:LTS | edk2 | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.10 | edk2 | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.04:LTS | edk2-hwe | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.10 | edk2-hwe | no fix listed | UBUNTU-CVE-2026-28389 |
| Ubuntu:22.04:LTS | openssl | 3.0.2-0ubuntu1.23 | UBUNTU-CVE-2026-28389 |
| Ubuntu:24.04:LTS | openssl | 3.0.13-0ubuntu3.9 | UBUNTU-CVE-2026-28389 |
| Ubuntu:25.10 | openssl | 3.5.3-1ubuntu3.3 | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.04:LTS | openssl | 3.5.5-1ubuntu3 | UBUNTU-CVE-2026-28389 |
| Ubuntu:26.10 | openssl | 3.5.5-1ubuntu3 | UBUNTU-CVE-2026-28389 |
Affected products (as reported)
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H