CVE-2026-14587

Neo4j's Bolt modern handshake decoder treats an overlong capability bit mask the same way it treats a truncated bit mask. When an unauthenticated client sends a selected protocol version followed by 32 continuation bytes in the capability mask, the decoder resets the reader index and waits for more bytes instead of rejecting the protocol message and closing the channel. Because the same unread bytes remain at the front of the decoder buffer, appending a terminating byte later does not recover the connection. The decoder re-reads the same first 32 continuation bytes, returns without producing a handshake-finalization message, and leaves the channel open. This can be triggered before authentication by any client that can reach the Bolt connector.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://neo4j.com/security/CVE-2026-14587	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:neo4j:neo4j:::::community:::*
	cpe:2.3:a:neo4j:neo4j:::::enterprise:::*
	cpe:2.3:a:neo4j:neo4j:::::community:::*
	cpe:2.3:a:neo4j:neo4j:::::enterprise:::*

History

No history.

Information

Published : 2026-08-05 17:16

Updated : 2026-08-28 16:08

NVD link : CVE-2026-14587

Mitre link : CVE-2026-14587

CVE.ORG link : CVE-2026-14587

JSON object : View

Products Affected

neo4j

neo4j

CWE

CWE-130

Improper Handling of Length Parameter Inconsistency

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