CVE-2026-14587Network attack vector

Pre-authentication denial of service via overlong capability mask

Published Aug 5, 2026 · Updated Aug 5, 2026

Denial of service in Neo4j Community and Enterprise Editions before 5.26.29 or 2026.07 allows remote attackers to hold Bolt channels open. The modern handshake decoder resets its reader index after 32 continuation bytes in a capability mask and repeatedly waits on the same unread bytes instead of rejecting the overlong field. Any unauthenticated client that can reach the Bolt connector can retain a channel without completing authentication.

CVSS severity7.5
High
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Neo4j Community and Enterprise Editions before 5.26.29 or 2026.07 allows remote attackers to hold Bolt channels open. The modern handshake decoder resets its reader index after 32 continuation bytes in a capability mask and repeatedly waits on the same unread bytes instead of rejecting the overlong field. Any unauthenticated client that can reach the Bolt connector can retain a channel without completing authentication.

The record

CVE
CVE-2026-14587
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
Neo4j
Product
Neo4j Enterprise Edition
Classifications
CWE-130, CAPEC-227, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2025.01 <2026.07
  2. Affected versionversion=5.0 <5.26.29

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Neo4j · Neo4j Enterprise Editionversion=2025.01 <2026.07; version=5.0 <5.26.29
Neo4j · Neo4j Community Editionversion=2025.01 <2026.07; version=5.0 <5.26.29

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.5Neo4jCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-130Improper Handling of Length Parameter Inconsistency
CAPEC-227Sustained Client Engagement
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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