Description
A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers.
Problem types
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Product status
Timeline
| 2025-12-11: | Reported to Red Hat. |
| 2025-12-11: | Made public. |
Credits
Red Hat would like to thank Ky0toFu and Sovereign Tech Resilience program for reporting this issue.
References
access.redhat.com/security/cve/CVE-2025-14523
bugzilla.redhat.com/show_bug.cgi?id=2421349 (RHBZ#2421349)
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