Input validation error in OpenSSL - CVE-2026-34181
Published: June 10, 2026
Vulnerability identifier: #VU134279
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-34181
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: OpenSSL Software Foundation
Affected software:
OpenSSL
OpenSSL
Detailed vulnerability description
The vulnerability allows a remote attacker to impersonate a user.
The vulnerability exists due to improper input validation in PKCS#12 file processing for PBMAC1 integrity verification when processing unencrypted PKCS#12 files with a one-byte HMAC key. A remote attacker can submit a crafted PKCS#12 file to impersonate a user.
The forged file is accepted with a 1 in 256 probability.
How to mitigate CVE-2026-34181
Install security update from vendor's website.