SB2026041427 - IBM z/Transaction Processing Facility update for cryptography
Published: April 14, 2026
Security Bulletin ID
SB2026041427
Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Improper Certificate Validation (CVE-ID: CVE-2026-34073)
The vulnerability allows a remote attacker to bypass certificate name constraints validation.
The vulnerability exists due to improper certificate validation in the X.509 certificate validation logic when validating a peer name against a wildcard SAN certificate chain. A remote attacker can present a crafted certificate chain to bypass certificate name constraints validation.
Exploitation requires an uncommon X.509 topology involving an excluded subtree constraint that matches the peer name.
Remediation
Install update from vendor's website.