CVE-2026-88406Network attack vector

Database crash via unbounded RETURN projection array

Published Sep 21, 2026 · Updated Sep 21, 2026

Stack overflow in FalkorDB 4.20.1 through 4.20.4 allows remote attackers to crash the database with a crafted graph query. _ValidateUnion_Clauses allocates a stack array sized directly from the unbounded number of client-supplied RETURN projections, exhausting the thread stack and causing SIGSEGV. GRAPH.QUERY permission is required; open instances need no credentials, while protected instances require authentication, and termination loses non-persisted graph data.

CVSS severity7.5
High
EPSS probability0.46%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack overflow in FalkorDB 4.20.1 through 4.20.4 allows remote attackers to crash the database with a crafted graph query. _ValidateUnion_Clauses allocates a stack array sized directly from the unbounded number of client-supplied RETURN projections, exhausting the thread stack and causing SIGSEGV. GRAPH.QUERY permission is required; open instances need no credentials, while protected instances require authentication, and termination loses non-persisted graph data.

The record

CVE
CVE-2026-88406
Published
Sep 21, 2026
Updated
Sep 21, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 21, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.5FalkorDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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