CVE-2018-0765

A denial of service vulnerability exists when .NET and .NET Core improperly process XML documents, aka ".NET and .NET Core Denial of Service Vulnerability." This affects Microsoft .NET Framework 2.0, Microsoft .NET Framework 3.0, Microsoft .NET Framework 4.7.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2/4.7/4.7.1, Microsoft .NET Framework 4.5.2, Microsoft .NET Framework 4.7/4.7.1, Microsoft .NET Framework 4.6, Microsoft .NET Framework 3.5, Microsoft .NET Framework 3.5.1, Microsoft .NET Framework 4.6/4.6.1/4.6.2, Microsoft .NET Framework 4.6.2/4.7/4.7.1, .NET Core 2.0, Microsoft .NET Framework 4.7.2.

An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs. Typical impact: local file disclosure, server-side request forgery, or denial of service.

CVE-2018-0765 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.4.2); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2018-0765? CVE-2018-0765 is a high-severity XML external entity injection (XXE) vulnerability in System.Security.Cryptography.Xml (nuget), affecting versions < 4.4.2. It is fixed in 4.4.2. An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs.
2. How severe is CVE-2018-0765? CVE-2018-0765 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of System.Security.Cryptography.Xml are affected by CVE-2018-0765? System.Security.Cryptography.Xml (nuget) versions < 4.4.2 is affected.
4. Is there a fix for CVE-2018-0765? Yes. CVE-2018-0765 is fixed in 4.4.2. Upgrade to this version or later.
5. Is CVE-2018-0765 exploitable, and should I be worried? Whether CVE-2018-0765 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2018-0765 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2018-0765? Upgrade System.Security.Cryptography.Xml to 4.4.2 or later.