CVE-2026-34181

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.

How to fix CVE-2026-34181

To remediate CVE-2026-34181, upgrade the affected package to a fixed version below.

• —upgrade to 3.5.7-r0 or later
• —upgrade to 3.5.6-1~deb13u2 or later

Is CVE-2026-34181 being exploited?

No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-34181.

Affected packages (2)

• from 0, < 3.5.7-r0
• from 0, < 3.5.6-1~deb13u2

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2026-34181
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-34181