CVE-2026-92877 in jaxb-ri
Summary
by MITRE • 10/12/2026
The JAXB factory methods historically relied solely on `FEATURE_SECURE_PROCESSING` to prevent XML External Entity (XXE) resolution. On JAXP implementations where that feature alone does not block external entity resolution, an attacker who can get untrusted XML unmarshalled through JAXB can read local files via out-of-band XXE.
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Analysis
by VulDB Data Team • 10/12/2026
The Java Architecture for XML Binding library has long been a primary mechanism for converting XML documents into Java objects and vice versa within enterprise applications. Historically, developers relied on the FEATURE_SECURE_PROCESSING flag provided by the underlying JAXP implementation to mitigate security risks associated with XML parsing, particularly regarding resource exhaustion and external entity resolution. This feature was intended to restrict certain non-security related features that could be abused for denial of service attacks or unauthorized data access. However, this reliance created a significant gap in defense-in-depth strategies because FEATURE_SECURE_PROCESSING does not universally disable the processing of External Entities across all JAXP implementations. In environments where the underlying parser continues to resolve external entities despite this flag being enabled, applications remain vulnerable to XML External Entity injection attacks that can lead to server-side request forgery and arbitrary file read vulnerabilities.
The technical flaw stems from the fact that JAXB delegates parsing tasks to the configured XML processor, such as those based on Xerces or other SAX/DOM parsers. When an attacker supplies a maliciously crafted XML document containing external entity declarations pointing to local system resources like file:///etc/passwd, the parser may resolve these entities if the specific implementation does not strictly enforce blocking of all external DTDs and entities under FEATURE_SECURE_PROCESSING. This behavior allows the application to inadvertently read sensitive files from the server's filesystem during the unmarshalling process. The vulnerability is particularly dangerous because it bypasses common security configurations that administrators might assume are sufficient for XML processing safety, leading to a false sense of security in production environments where JAXB is used extensively for data interchange.
The operational impact of this vulnerability includes unauthorized access to sensitive local files on the server hosting the vulnerable application. An attacker can exploit this flaw to exfiltrate configuration files containing database credentials, private keys, or other secrets stored locally. Furthermore, if the underlying parser supports out-of-band interactions, such as DNS lookups triggered by entity resolution, it may also facilitate Server-Side Request Forgery attacks against internal network resources that are not directly accessible from the internet. This can lead to further compromise of the internal infrastructure, allowing lateral movement and deeper penetration into protected networks. The severity is heightened in microservices architectures where one compromised service might be used as a pivot point to attack other services within the same cluster or VPC.
To mitigate this risk, organizations must move beyond relying solely on FEATURE_SECURE_PROCESSING for XML security. It is critical to explicitly disable external entity resolution at the parser level by setting specific features such as disallowing DOCTYPE declarations and disabling access to external general entities in both SAXParserFactory and DocumentBuilderFactory instances used by JAXB implementations. Additionally, applying the latest patches from Java vendors ensures that known implementation-specific gaps are closed. Input validation should also be implemented to sanitize XML inputs before processing, although this is less effective against complex parsing vulnerabilities than configuration hardening. Security teams should audit their codebases for any direct instantiation of parsers and ensure they adhere to OWASP guidelines for preventing XXE attacks by enforcing strict allow-lists for expected input formats and disabling unnecessary XML features globally across the application server infrastructure.