CVE-2026-45447
Published:June 09, 2026
Updated:June 11, 2026
Issue summary: A specially crafted PKCS#7 or S/MIME signed message could
trigger a use-after-free during PKCS#7 signature verification.
Impact summary: A use-after-free may result in process crashes, heap
corruption, or potentially remote code execution.
When processing a PKCS#7 or S/MIME signed message, if the SignedData
digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may
incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent
use of the BIO by the calling application results in a use-after-free
condition.
In the common case this occurs when the application later calls
BIO_free() on the BIO originally passed to PKCS7_verify(). Depending
on allocator behavior and application-specific BIO usage patterns, this
may result in a crash or other memory corruption. In some application
contexts this may potentially be exploitable for remote code execution.
Applications that process PKCS#7 or S/MIME signed messages using OpenSSL
PKCS#7 APIs may be affected. Applications using the CMS APIs for this
processing are not affected.
The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this
issue, as the affected code is outside the OpenSSL FIPS module boundary.
Affected Packages
openssl (CONDA):
Affected version(s) >=3.6.0 <3.6.3Fix Suggestion:
Update to version 3.6.3openssl (CONDA):
Affected version(s) >=3.4.0 <3.4.6Fix Suggestion:
Update to version 3.4.6openssl (CONDA):
Affected version(s) >=3.5.0 <3.5.7Fix Suggestion:
Update to version 3.5.7openssl (CONDA):
Affected version(s) >=3.0.0 <3.0.21Fix Suggestion:
Update to version 3.0.21https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.4.0 <openssl-3.4.6Fix Suggestion:
Update to version openssl-3.4.6https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.0.0 <openssl-3.0.21Fix Suggestion:
Update to version openssl-3.0.21https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.6.0 <openssl-3.6.3Fix Suggestion:
Update to version openssl-3.6.3https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) >=openssl-3.5.0 <openssl-3.5.7Fix Suggestion:
Update to version openssl-3.5.7https://github.com/openssl/openssl.git (GITHUB):
Affected version(s) =openssl-4.0.0 <openssl-4.0.1Fix Suggestion:
Update to version openssl-4.0.1Related Resources (11)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Use After Free
EPSS
Base Score:
0.11