Vulnerability · Published Apr 17, 2026 · Assigned by GitHub_M

CVE-2026-35402mcp-neo4j-cypher: SSRF and Data Modification via read_only Mode Bypass Through CALL Procedures

Low 2.3

In plain English

A low-severity improper access control in mcp-neo4j from neo4j-contrib. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)2.3Low

Exploit odds (30 days)0.3%top 81.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

mcp-neo4j-cypher is an MCP server for executing Cypher queries against Neo4j databases. In versions prior to 0.6.0, the read_only mode enforcement can be bypassed using APOC CALL procedures, potentially allowing unauthorized write operations or server-side request forgery. This issue is fixed in version 0.6.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	mcp-neo4j-cypher	0.6.0	GHSA-x3cv-r3g3-fpg9
PyPI	mcp-neo4j-cypher	0.6.0	PYSEC-2026-2626

Affected products (as reported)

Vendor	Product	Versions
neo4j-contrib	mcp-neo4j	< 0.6.0

Weakness: CWE-284 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

References

https://github.com/neo4j-contrib/mcp-neo4j/security/advisories/GHSA-x3cv-r3g3-fpg9 x_refsource_CONFIRM
https://github.com/neo4j-contrib/mcp-neo4j/releases/tag/mcp-neo4j-cypher-v0.6.0 x_refsource_MISC