CVE-2026-87290 in Java SE
Summary
by MITRE • 10/21/2026
Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: JAXP). Supported versions that are affected are Oracle Java SE: 8u503, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27; Oracle GraalVM for JDK: 17.0.20.1 and 21.0.12.1; Oracle GraalVM Enterprise Edition: 21.3.19.1.1. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized access to critical data or complete access to all Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 5.9 (Confidentiality impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the JAXP component of Oracle Java SE, as well as in supported versions of Oracle GraalVM for JDK and Oracle GraalVM Enterprise Edition. This security flaw affects a broad range of releases including Oracle Java SE 8u503, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, and 25.0.4.1, alongside specific GraalVM releases such as 17.0.20.1, 21.0.12.1, and Enterprise Edition 21.3.19.1.1. The JAXP component is responsible for processing XML documents using Java APIs, a critical function in many enterprise applications that handle data interchange, configuration files, or web service payloads. The presence of this vulnerability indicates a fundamental weakness in how the parser handles certain inputs, potentially allowing an attacker to bypass expected security boundaries when untrusted XML content is processed.
The technical nature of this flaw allows for unauthorized access to critical data with complete access to all accessible information within the Java environment. Although the CVSS 3.1 base score is rated at 5.9 indicating a medium severity, primarily due to confidentiality impacts rather than integrity or availability loss, the implications are severe for applications relying on JAXP. The vulnerability is characterized as difficult to exploit and requires an unauthenticated attacker with network access via multiple protocols. This suggests that while remote exploitation is possible without prior authentication credentials, it demands specific conditions or precise input crafting that may not be trivially achievable in all contexts. However, the risk remains significant because successful exploitation leads directly to data exfiltration, compromising the confidentiality of sensitive information processed by the affected Java applications.
Operational impact extends beyond simple remote code execution scenarios into areas involving untrusted code loading and sandboxed environments. The vulnerability can be exploited through APIs within the specified component, particularly when a web service supplies maliciously crafted data to these APIs. This is especially dangerous for Java deployments that load and run untrusted code from external sources, such as clients running sandboxed Java Web Start applications or sandboxed Java applets. These environments typically rely on the Java security manager and sandboxing mechanisms to restrict what untrusted code can do. If the JAXP component fails to properly validate or sanitize input before processing, it may allow malicious XML structures to bypass these sandboxes, leading to unauthorized access to resources that should remain protected by the application's security model.
From a classification perspective, this vulnerability aligns with CWE-20 Improper Input Validation and potentially CWE-611 Improper Restriction of XML External Entity References if external entity processing is involved in the exploitation path. In terms of adversary tactics, it maps to ATT&CK technique T1553 Subvert Trust Controls which involves bypassing security mechanisms like sandboxes or code signing checks by exploiting flaws in trusted components. The attack vector AV:N indicates network accessibility, while AC:H reflects the high complexity required for successful exploitation. PR:N signifies that no privileges are needed initially, and S:U shows that the impact is confined to the vulnerable component's scope without escalating to affect other system resources directly, although data access within that scope is fully compromised.
Mitigation strategies must focus on immediate patching of all affected Oracle Java SE, GraalVM for JDK, and GraalVM Enterprise Edition versions to their latest secure releases provided by Oracle. Organizations should also implement strict input validation at the application layer before passing XML content to JAXP parsers, ensuring that only expected data structures are processed. Disabling unnecessary features such as external entity resolution if not required can further reduce the attack surface. For deployments involving Java Web Start or applets, it is crucial to review security policies and consider migrating away from deprecated technologies like applets which have inherent risks in modern web environments. Regular vulnerability scanning and monitoring for new advisories related to JAXP are essential to maintain a robust defense posture against evolving threats targeting XML processing libraries.