CVE-2026-113582 in Abdera
Summary
by MITRE • 10/22/2026
UNSUPPORTED WHEN ASSIGNED Improper restriction of XML external entity references in Apache Abdera allows an attacker to access sensitive data or make server-side requests when an application parses attacker-controlled XML with Abdera.
This issue affects Apache Abdera: all versions.
Apache Abdera is retired and no longer supported, so we do not plan to release a version that fixes this issue. Users are recommended to migrate to a maintained alternative. Applications that cannot migrate should ensure that untrusted XML cannot reach the affected Abdera parser or JDBC adapter parsing paths. Actively maintained downstream products may still be impacted if they include an affected Abdera artifact.
NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
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Analysis
by VulDB Data Team • 10/22/2026
The identified vulnerability represents a critical failure in input validation within Apache Abdera, specifically concerning the handling of XML external entity references. As a retired and unsupported component, this library lacks active maintenance or security patches, leaving any systems still relying on it exposed to significant risk. The core technical flaw lies in the parser's inability to properly restrict the resolution of External Entity declarations defined within processed XML documents. When an application utilizes Abdera to parse user-supplied or otherwise untrusted XML content, the underlying processing engine allows for the instantiation and expansion of these entities without adequate safeguards against malicious intent. This behavior deviates from secure coding practices that mandate strict validation of all external resources referenced during parsing operations.
From a technical perspective, this flaw aligns with CWE-611, which describes Improper Restriction of XML External Entity Reference. The vulnerability enables an attacker to craft specific XML payloads containing entity definitions that point to internal or sensitive file systems on the host server. Upon processing such input, the Abdera parser resolves these entities, effectively reading and returning the contents of restricted files to the application layer. This mechanism facilitates Server-Side Request Forgery scenarios where the server acts as a proxy for arbitrary requests initiated by an attacker. The operational impact is severe, potentially leading to unauthorized disclosure of sensitive data such as configuration files, credentials, or internal network structures that are not otherwise accessible through standard application interfaces.
The risk landscape is further complicated by the fact that Apache Abdera has reached its end-of-life status and is no longer supported by its maintainer. Consequently, there will be no official patch released to remediate this issue within the library itself. This necessitates a shift in mitigation strategy from simple software updates to architectural changes or compensating controls. Organizations continuing to use legacy systems that depend on Abdera must recognize that they are operating with known, unpatched vulnerabilities. The responsibility for security shifts entirely to the application developers and system administrators who must implement defensive measures at the integration layer rather than relying on library-level fixes.
To mitigate this risk in environments where migration is not immediately feasible, it is imperative to ensure that untrusted XML data never reaches the Abdera parser or any JDBC adapter parsing paths associated with it. This can be achieved by implementing strict input validation and sanitization routines before the data is passed to the vulnerable component. Additionally, deploying a Web Application Firewall configured to detect and block known patterns of XXE attacks can provide an additional layer of defense. However, these measures are compensatory and do not eliminate the underlying vulnerability; they merely reduce the attack surface by preventing malicious payloads from reaching the flawed code execution path.
For long-term security posture improvement, migrating away from Apache Abdera to a maintained alternative is strongly recommended. Modern XML processing libraries typically include built-in protections against XXE vulnerabilities by default or offer configurable options that enforce secure parsing behaviors such as disabling DTDs and external entities entirely. By transitioning to actively supported software, organizations can ensure access to future security updates and align with current industry standards for secure application development. This migration reduces the technical debt associated with legacy components and mitigates the risk of exploitation through more robust, community-vetted codebases that adhere to contemporary cybersecurity best practices.