{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "ac6c3f94d38505bc0facea286a4d3728044c6e5c"
            }
          ],
          "repo": "https://github.com/zaproxy/zap-extensions",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-502"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57527.json"
  },
  "details": "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.",
  "id": "CVE-2026-57527",
  "modified": "2026-07-16T03:30:54.212937524Z",
  "published": "2026-06-26T14:43:32.982Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57527.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/zaproxy/zap-extensions/releases/tag/viewstate-v4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-57527"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/zap-viewstate-add-on-insecure-deserialization-via-jsfviewstate-decode"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.zaproxy.org/blog/2026-06-24-java-deserialization-vulnerability-in-zap-viewstate-addon/"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/zaproxy/zap-extensions/pull/7481"
    },
    {
      "type": "FIX",
      "url": "https://github.com/zaproxy/zap-extensions/commit/ac6c3f94d38505bc0facea286a4d3728044c6e5c"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zaproxy/zap-extensions"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "ZAP ViewState Add-on Insecure Deserialization via JSFViewState.decode()"
}