SB2025061854 - IBM Fusion and IBM Fusion HCI update for python package h11
Published: June 18, 2025
Security Bulletin ID
SB2025061854
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) Inconsistent interpretation of HTTP requests (CVE-ID: CVE-2025-43859)
The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.
The vulnerability exists due to improper validation of HTTP requests in h11/_readers.py. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.
Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.
Remediation
Install update from vendor's website.