Unauthenticated cache poisoning via unvalidated Host header
Published Feb 4, 2026 · Updated Feb 4, 2026
HTTP header injection in IBM Concert 1.0.0 through 2.1.0 allows remote attackers to poison caches or hijack sessions via Host headers. Concert's HTTP request handling accepts an attacker-controlled Host value without proper validation before using it in HTTP headers. No authentication or user interaction is required; IBM has not identified the exact handler, but reports XSS, cache poisoning, and session hijacking.
Summary
What happened
HTTP header injection in IBM Concert 1.0.0 through 2.1.0 allows remote attackers to poison caches or hijack sessions via Host headers. Concert's HTTP request handling accepts an attacker-controlled Host value without proper validation before using it in HTTP headers. No authentication or user interaction is required; IBM has not identified the exact handler, but reports XSS, cache poisoning, and session hijacking.
The record
- CVE
- CVE-2024-51451
- Published
- Feb 4, 2026
- Updated
- Feb 4, 2026
- Vendor
- IBM
- Product
- Concert
- Classifications
- CWE-644, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 4, 2026CVE publishedPublication date reported by the CVE source.
- Feb 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.0.0 <=2.1.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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