CVE-2026-34181
Description
A flaw was found in OpenSSL. This vulnerability allows a remote attacker to forge PKCS#12 (Public-Key Cryptography Standards #12) files that use Password-Based Message Authentication Code 1 (PBMAC1) with short HMAC (Hash-based Message Authentication Code) keys. This can lead to a service accepting attacker-controlled certificates and private keys with a 1 in 256 probability, potentially enabling impersonation.
Statement
Low: This flaw allows an attacker to forge PKCS#12 files with a 1 in 256 probability, leading to the acceptance of attacker-controlled certificates and private keys by services configured to use PBMAC1 authentication. Red Hat products utilizing OpenSSL versions 3.0, 1.1.1, or 1.0.2 are not affected, as these versions do not support PBMAC1 in PKCS#12.
Mitigation
To mitigate this issue, enforce strict validation on all uploaded PKCS#12 files to reject those containing abnormally short security keys. Additionally, enabling FIPS mode on your system can help protect your environment, as the vulnerable OpenSSL code operates entirely outside the approved FIPS cryptographic boundary.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.3 | N/A | 7.4 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Integrity,Confidentiality
Technical Impact: Gain Privileges or Assume Identity; Modify Application Data; Execute Unauthorized Code or Commands
An attacker could gain access to sensitive data and possibly execute unauthorized code.
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