Neo4j Labs MCP Servers: SSRF and Data Modification via read_only Mode Bypass Through CALL ProceduresGHSA-x3cv-r3g3-fpg9
GHSA-x3cv-r3g3-fpg9 is a CWE-284 vulnerability in mcp-neo4j-cypher. A fix is available for mcp-neo4j-cypher — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-x3cv-r3g3-fpg9.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
mcp-neo4j-cypherReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The read_only mode in mcp-neo4j-cypher versions prior to 0.6.0 can be bypassed using CALL procedures.
Details
Impact
The enforcing of read_only mode in vulnerable versions could be bypassed by certain APOC procedures.
Patches
v0.6.0 release hardened the checks around the mode. The only way to guarantee the server actions is to limit the permissions of the db credentials available to the server.
Notes
Impacts for server-side request forgery vulnerabilities may depend on both the configuration of the vulnerable system as well as the presence of other systems in the environment that could be accessed as part of exploitation.
Recommended hardening
- Limit the apoc procedures to what's required
- Manage data loading privileges
- Don't relax the default settings without compensating controls
apoc.import.file.enabledisfalseby defaultapoc.import.file.use_neo4j_configistrueby default to restrict file imports to the import folder
Credits
We want to publicly recognise the contribution of Yotam Perkal from Pluto Security.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | mcp-neo4j-cypher | all versions | 0.6.0pip install --upgrade 'mcp-neo4j-cypher==0.6.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mcp-neo4j-cypher, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mcp-neo4j-cypher to 0.6.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-x3cv-r3g3-fpg9 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is GHSA-x3cv-r3g3-fpg9 in your dependencies?
Find it across PyPI, including transitive dependencies.