Remote code execution via tampered filter-state cookie
Published Apr 22, 2026 · Updated Apr 22, 2026
Insecure deserialization in Telerik UI for ASP.NET AJAX 2024.4.1114 through 2026.1.225 allows remote attackers to execute server-side code. RadFilter's LoadState() path deserializes persisted filter state read from a configured CookieStateStorageProvider HTTP cookie without protecting it from tampering. Exploitation requires RadFilter and RadPersistenceManager on the page, cookie-backed custom storage, and a LoadState() call; the safe default stores state server-side.
Summary
What happened
Insecure deserialization in Telerik UI for ASP.NET AJAX 2024.4.1114 through 2026.1.225 allows remote attackers to execute server-side code. RadFilter's LoadState() path deserializes persisted filter state read from a configured CookieStateStorageProvider HTTP cookie without protecting it from tampering. Exploitation requires RadFilter and RadPersistenceManager on the page, cookie-backed custom storage, and a LoadState() call; the safe default stores state server-side.
The record
- CVE
- CVE-2026-6023
- Published
- Apr 22, 2026
- Updated
- Apr 22, 2026
- Vendor
- Progress Software Corporation
- Product
- Telerik UI for ASP.NET AJAX
- Classifications
- CWE-502, CAPEC-586, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 22, 2026CVE publishedPublication date reported by the CVE source.
- Apr 22, 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=2024.4.1114 <2026.1.421
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
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Technologies
Your stack
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Your stack
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