CVE-2026-3511
Improper Restriction of XML External Entity Reference vulnerability in XMLUtils.
Executive Summary
CVE-2026-3511 is a high severity vulnerability affecting appsec, ai-code. It is classified as XXE Injection. Ensure your systems and dependencies are patched immediately to mitigate exposure risks.
Precogs AI Insight
"The defect is inherently caused by within Improper Restriction of XML External Entity Reference vulnerability, allowing a lack of rigorous type checking mechanisms. A threat actor could leverage this oversight to trigger a denial of service state, crashing critical operational components. The Precogs AI's Code Property Graph analysis traces untrusted input to harden the environment against lateral movement."
What is this vulnerability?
CVE-2026-3511 is categorized as a critical Application Verification Flaw flaw. Based on our vulnerability intelligence, this issue occurs when the application fails to securely handle untrusted data boundaries.
Improper Restriction of XML External Entity Reference vulnerability in XMLUtils.java in Slovensko.Digital Autogram allows remote unauthenticated attacker t...
This architectural defect enables adversaries to bypass intended security controls, directly manipulating the application's execution state or data layer. Immediate strategic intervention is required.
Risk Assessment
| Metric | Value |
|---|---|
| CVSS Base Score | 8.6 (HIGH) |
| Vector String | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N |
| Published | March 19, 2026 |
| Last Modified | March 19, 2026 |
| Related CWEs | CWE-611 |
Impact on Systems
✅ Unauthorized Access: Flaws in application logic can permit unauthorized interaction with protected APIs.
✅ Data Manipulation: Adversaries may alter critical application states, such as user roles or configurations.
✅ Service Disruption: Improper error handling or unvalidated inputs can lead to resource exhaustion.
How to fix this issue?
Implement the following strategic mitigations immediately to eliminate the attack surface.
1. Defense in Depth Implement multi-layered validation (client-side, API gateway, and server-side).
2. Least Privilege Ensure backend service accounts operate with the absolute minimum rights required.
3. Security Regression Testing Integrate automated semantic security scanning into the deployment pipeline.
Vulnerability Signature
// Generic Application Security Flaw (Node.js)
app.post('/api/update-profile', (req, res) =\> \{
// DANGEROUS: Mass Assignment / Object Injection
// Attacker can pass \{ "isAdmin": true, "email": "..." \}
User.update(\{ id: req.user.id \}, req.body);
// SECURED: Explicitly select permitted fields
const \{ email, displayName, bio \} = req.body;
User.update(\{ id: req.user.id \}, \{ email, displayName, bio \});
\});
References and Sources
- NVD — CVE-2026-3511
- MITRE — CVE-2026-3511
- CWE-611 — MITRE CWE
- CWE-611 Details
- Application Security Vulnerabilities
- AI Code Security Vulnerabilities
Vulnerability Code Signature
Attack Data Flow
| Stage | Detail |
|---|---|
| Source | User-supplied XML payload |
| Vector | XML parser resolves external entities |
| Sink | XML parsing function |
| Impact | Information disclosure, Server-Side Request Forgery (SSRF) |
Vulnerable Code Pattern
// ❌ VULNERABLE: XXE Injection
public void parseXml(InputStream is) throws Exception {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
// Taint sink: default configuration allows external entities
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(is);
}
Secure Code Pattern
// ✅ SECURE: Safe XML Parsing
public void parseXml(InputStream is) throws Exception {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
// Sanitized configuration: disable external entities
factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
DocumentBuilder builder = factory.newDocumentBuilder();
Document doc = builder.parse(is);
}
How Precogs Detects This
Precogs AI Analysis Engine identifies unsafe XML parsing configurations and XXE injection weaknesses via inter-procedural taint tracking.\n