CVE-2026-57527 | Zed Attack Proxy (ZAP) ViewState add-on before version 4 con… | CVSS 8.8 HIGH

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.

Metadata

CVE ID: CVE-2026-57527
State: PUBLISHED
Assigner: VulnCheck
Reserved: 2026-06-24 15:58 UTC
Published: 2026-06-26 14:43 UTC
Last updated: 2026-06-26 16:31 UTC
Primary CWE: CWE-502
Deserialization of Untrusted Data
Vendor / Product: zaproxy / zap-extensions
Sources: cve.org · NVD

Severity & Metrics

8.8 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
zaproxy	zap-extensions	—	0 < 4

Weakness (CWE)

CWE	Source	Description
CWE-502	cna	Deserialization of Untrusted Data

CVSS scores (2)

Score	Severity	Version	Source	Vector
8.8	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.7	HIGH	4.0	cna	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References (5)