CSP bypass via premature header generation
Published Jul 27, 2026 · Updated Jul 27, 2026
Protection mechanism failure in Apache Wicket 9.0.0 through 9.23.0 and 10.0.0 through 10.9.0 allows remote attackers to bypass CSP. The CSPRequestCycleListener generates and writes policy headers before final WebPage rendering, allowing redirects or response resets to leak a nonce or omit the header from the delivered page. Exploitation requires an application to enable Wicket CSP and reach an affected redirect flow; the flaw weakens script restrictions but does not itself inject script.
Summary
What happened
Protection mechanism failure in Apache Wicket 9.0.0 through 9.23.0 and 10.0.0 through 10.9.0 allows remote attackers to bypass CSP. The CSPRequestCycleListener generates and writes policy headers before final WebPage rendering, allowing redirects or response resets to leak a nonce or omit the header from the delivered page. Exploitation requires an application to enable Wicket CSP and reach an affected redirect flow; the flaw weakens script restrictions but does not itself inject script.
The record
- CVE
- CVE-2026-66391
- Published
- Jul 27, 2026
- Updated
- Jul 27, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache Wicket
- Classifications
- CWE-693, CWE-330
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 27, 2026CVE publishedPublication date reported by the CVE source.
- Jul 27, 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?
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- Affected versionversion=10.0.0 <=10.9.0
- Affected versionversion=9.0.0 <=9.23.0
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
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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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