CVE-2026-34181
Published:June 09, 2026
Updated:August 06, 2026
Issue Summary: The PKCS#12 file processing fails to perform sufficient input
validation for files that use Password-Based Message Authentication Code 1
(PBMAC1) integrity mechanism allowing a certificate and private key forgery.
Impact Summary: An attacker impersonating a user can cause a service reading
PKCS#12 files to accept forged certificates and private keys with a 1 in 256
probability.
If a service accepting PKCS#12 files is using passwords for authenticating
the received files, the attacker can create unencrypted PKCS#12 files that
use PBMAC1 authentication that specifies an HMAC key of only one byte, allowing
them to craft a file that will be accepted with a 1 in 256 probability.
That would then cause the service to accept a certificate and private key
controlled by the attacker.
The FIPS modules are not affected by this issue, as the affected code is
outside the OpenSSL FIPS module boundary.
Affected Packages
openssl (CONDA):
Affected version(s) >=3.5.0 <3.5.7Fix Suggestion:
Update to version 3.5.7openssl (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 3.4.6https://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-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-3.6.0 <openssl-3.6.3Fix Suggestion:
Update to version openssl-3.6.3https://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:
9.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Validation of Integrity Check Value
EPSS
Base Score:
0.24