Summary
XML External Entity (XXE) vulnerability in apoc.import.graphml
Workarounds
If you cannot upgrade the library, you can control the allowlist of the procedures that can be used in your system.
For more information
If you have any questions or comments about this advisory:
- Open an issue in neo4j-apoc
- Email us at [email protected]
Credits
We want to publicly recognise the contribution of Christopher Schneider, State Farm.
Impact
A XML External Entity (XXE) vulnerability found in the apoc.import.graphml procedure of APOC core plugin in Neo4j graph database. XML External Entity (XXE) injection occurs when the XML parser allows external entities to be resolved. The XML parser used by the apoc.import.graphml procedure was not configured in a secure way and therefore allowed this.
External entities can be used to read local files, send HTTP requests, and perform denial-of-service attacks on the application.
Abusing the XXE vulnerability enabled assessors to read local files remotely. Although with the level of privileges assessors had this was limited to one-line files. With the ability to write to the database, any file could have been read. Additionally, assessors noted, with local testing, the server could be crashed by passing in improperly formatted XML.
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-2023-23926 has a CVSS score of 5.9 (Medium). The vector is network-reachable, low 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 (5.5.0, 4.4.0.14); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The users should aim to use the latest released version compatible with their Neo4j version. The minimum versions containing patch for this vulnerability is 5.5.0.
Frequently Asked Questions
- What is CVE-2023-23926? CVE-2023-23926 is a medium-severity XML external entity injection (XXE) vulnerability in org.neo4j.procedure:apoc-core (maven), affecting versions >= 5.0.0, < 5.5.0. It is fixed in 5.5.0, 4.4.0.14. An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs.
- How severe is CVE-2023-23926? CVE-2023-23926 has a CVSS score of 5.9 (Medium). 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.
- Which versions of org.neo4j.procedure:apoc-core are affected by CVE-2023-23926? org.neo4j.procedure:apoc-core (maven) versions >= 5.0.0, < 5.5.0 is affected.
- Is there a fix for CVE-2023-23926? Yes. CVE-2023-23926 is fixed in 5.5.0, 4.4.0.14. Upgrade to this version or later.
- Is CVE-2023-23926 exploitable, and should I be worried? Whether CVE-2023-23926 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
- What actually determines whether CVE-2023-23926 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.
- How do I fix CVE-2023-23926?
- Upgrade
org.neo4j.procedure:apoc-coreto 5.5.0 or later - Upgrade
org.neo4j.procedure:apoc-coreto 4.4.0.14 or later
- Upgrade