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veraPDF Validation XXE via XFA

High severity GitHub Reviewed Published Jun 8, 2026 in veraPDF/veraPDF-validation • Updated Jul 29, 2026

Package

maven org.verapdf:validation-model (Maven)

Affected versions

>= 1.17.35, <= 1.30.1
>= 1.31.1, <= 1.31.70

Patched versions

1.30.2
1.31.71
maven org.verapdf:validation-model-jakarta (Maven)
>= 1.17.35, <= 1.30.1
>= 1.31.1, <= 1.31.70
1.30.2
1.31.71

Description

Summary

Description
An XML External Entity Injection (CWE-611) vulnerability in veraPDF allows a remote attacker to read arbitrary files on the server file system and perform Server-Side Request Forgery by submitting a crafted PDF containing a malicious XFA stream. This affects all current versions of veraPDF-validation.

Details

The vulnerability resides in veraPDF-validation validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDAcroForm.java within the getdynamicRender() method. This method retrieves the /XFA entry from the PDF's /AcroForm dictionary, decodes the embedded XML stream, and parses it to extract the <dynamicRender> element value.

The vulnerability stems from the use of a default-configured DocumentBuilderFactory to parse fully attacker-controlled XML:

  • The factory is created via DocumentBuilderFactory.newInstance() with no security features enabled. disallow-doctype-decl, external-general-entities, external-parameter-entities, and FEATURE_SECURE_PROCESSING are all left at their insecure defaults.
  • The input passed to builder.parse() is the decoded /XFA stream taken directly from the untrusted PDF.
  • The text content of the <dynamicRender> node is returned to the validation model. Note that the shipped PDF/UA-1 rule (dynamicRender != 'required') consumes this value but does not echo it into the report output, so reliable exfiltration requires the out-of-band parameter-entity technique described under Impact rather than in-band reflection.

Impact

This impacts all current releases of the veraPDF validation-model module.

Successful exploitation requires only that the target validate an attacker-supplied PDF against the PDF/UA-1 profile (or via flavour auto-detection on a PDF that declares PDF/UA-1 conformance), since getdynamicRender() is invoked by the dynamicRender != 'required' rule in the bundled PDF/UA-1 profile. No additional configuration or operator action is required.

Proposed Patch

Harden the DocumentBuilderFactory in validation-model/src/main/java/org/verapdf/gf/model/impl/pd/GFPDAcroForm.java per the OWASP XXE Prevention Cheat Sheet to disallow DOCTYPE outright.

References

@bdoubrov bdoubrov published to veraPDF/veraPDF-validation Jun 8, 2026
Published to the GitHub Advisory Database Jul 29, 2026
Reviewed Jul 29, 2026
Last updated Jul 29, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity None
Availability None
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(24th percentile)

Weaknesses

Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. Learn more on MITRE.

CVE ID

CVE-2026-54079

GHSA ID

GHSA-36mm-w85j-3q2j

Source code

Credits

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