CVE-2026-57527
ZAP ViewState Add-on Insecure Deserialization via JSFViewState.decode()
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
Zed Attack Proxy (ZAP) ViewState add-on before version 4 contains an insecure deserialization vulnerability that allows attackers who control a proxied web server to achieve arbitrary code execution by embedding a malicious serialized Java object in the javax.faces.ViewState HTTP response parameter. The JSFViewState.decode() method base64-decodes the ViewState value and passes it directly to ObjectInputStream.readObject() without a deserialization filter, allowlist, or type restriction, causing the malicious object to be deserialized within the ZAP JVM when the Desktop UI renders the ViewState panel.
| CWE | CWE-502 |
| Vendor | zaproxy |
| Product | zap-extensions |
| Published | Jun 26, 2026 |
| Last Updated | Jun 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
zaproxy / zap-extensions
0 < 4
References
zaproxy.org: https://www.zaproxy.org/blog/2026-06-24-java-deserialization-vulnerability-in-zap-viewstate-addon/ github.com: https://github.com/zaproxy/zap-extensions/releases/tag/viewstate-v4 github.com: https://github.com/zaproxy/zap-extensions/pull/7481 github.com: https://github.com/zaproxy/zap-extensions/commit/ac6c3f94d38505bc0facea286a4d3728044c6e5c vulncheck.com: https://www.vulncheck.com/advisories/zap-viewstate-add-on-insecure-deserialization-via-jsfviewstate-decode
Credits
Neo by ProjectDiscovery