Credential disclosure via cross-host redirect header reuse
Published May 12, 2026 · Updated May 12, 2026
Information disclosure in affected Apache Tomcat releases allows remote attackers to read WebSocket authentication credentials. WsWebSocketContainer retains the latest Authorization header in userProperties and reuses it when following an HTTP redirect to another host. Exploitation requires an authenticated WebSocket client request followed by an attacker-controlled cross-host redirect, which exposes the reusable header to that host.
Summary
What happened
Information disclosure in affected Apache Tomcat releases allows remote attackers to read WebSocket authentication credentials. WsWebSocketContainer retains the latest Authorization header in userProperties and reuses it when following an HTTP redirect to another host. Exploitation requires an authenticated WebSocket client request followed by an attacker-controlled cross-host redirect, which exposes the reusable header to that host.
The record
- CVE
- CVE-2026-42498
- Published
- May 12, 2026
- Updated
- May 12, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Tomcat
- Classifications
- CWE-200
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 12, 2026CVE publishedPublication date reported by the CVE source.
- May 12, 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=10.1.0-M1 <=10.1.54
- Affected versionversion=11.0.0-M1 <=11.0.21
- Affected versionversion=7.0.83 <=7.0.109
- Affected versionversion=8.5.24 <=8.5.100
- Affected versionversion=9.0.2 <=9.0.117
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
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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