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.
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.
Project Subscriptions
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Advisories
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Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 09 Jun 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | PKCS#12 Files with PBMAC1 Are Accepted with Short HMAC Keys | |
| Weaknesses | CWE-354 | |
| References |
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Projects
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Status: PUBLISHED
Assigner: openssl
Published:
Updated: 2026-06-09T16:03:22.065Z
Reserved: 2026-03-26T09:29:36.013Z
Link: CVE-2026-34181
No data.
Status : Received
Published: 2026-06-09T17:17:04.740
Modified: 2026-06-09T17:17:04.740
Link: CVE-2026-34181
No data.
OpenCVE Enrichment
Updated: 2026-06-09T17:30:10Z
Weaknesses