CVE-2026-57527
ZAP ViewState Add-on Insecure Deserialization via JSFViewState.decode()
Description
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.
INFO
Published Date :
June 26, 2026, 3:16 p.m.
Last Modified :
Oct. 25, 2026, 6:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update the ZAP ViewState add-on to the latest version.
- Ensure ZAP and its add-ons are updated regularly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-57527.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-57527 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-57527
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-57527 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-57527 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Oct. 25, 2026
Action Type Old Value New Value Added Translation Title: zap-extensions de zaproxy, Description: El complemento ViewState de Zed Attack Proxy (ZAP) anterior a la versión 4 contiene una vulnerabilidad de deserialización insegura que permite a los atacantes que controlan un servidor web proxy lograr la ejecución de código arbitrario incrustando un objeto Java serializado malicioso en el parámetro de respuesta HTTP javax.faces.ViewState. El método JSFViewState.decode() decodifica en base64 el valor de ViewState y lo pasa directamente a ObjectInputStream.readObject() sin un filtro de deserialización, lista blanca o restricción de tipo, lo que provoca que el objeto malicioso sea deserializado dentro de la JVM de ZAP cuando la interfaz de usuario de escritorio renderiza el panel ViewState. -
CVE Modified by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://github.com/zaproxy/zap-extensions', 'vendor': 'zaproxy', 'product': 'zap-extensions', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '4', 'versionType': 'custom'}], 'defaultStatus': 'affected'}] [{'repo': 'https://github.com/zaproxy/zap-extensions', 'vendor': 'zaproxy', 'product': 'zap-extensions', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '4', 'versionType': 'custom'}], 'packageURL': 'pkg:github/zaproxy/zap-extensions', 'defaultStatus': 'affected'}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 26, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-57527', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-26T16:28:16.504067Z'} -
New CVE Received by [email protected]
Jun. 26, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/zaproxy/zap-extensions', 'vendor': 'zaproxy', 'product': 'zap-extensions', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '4', 'versionType': 'custom'}], 'defaultStatus': 'affected'}] Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-502 Added Reference https://github.com/zaproxy/zap-extensions/commit/ac6c3f94d38505bc0facea286a4d3728044c6e5c Added Reference https://github.com/zaproxy/zap-extensions/pull/7481 Added Reference https://github.com/zaproxy/zap-extensions/releases/tag/viewstate-v4 Added Reference https://www.vulncheck.com/advisories/zap-viewstate-add-on-insecure-deserialization-via-jsfviewstate-decode Added Reference https://www.zaproxy.org/blog/2026-06-24-java-deserialization-vulnerability-in-zap-viewstate-addon/