CVE-2023-54393Network attack vector

Server crash via malformed LoginPacket JSON

Published Sep 9, 2026 · Updated Sep 9, 2026

Improper input validation in PocketMine-MP before 4.20.5 allows remote attackers to crash the server via malformed LoginPacket JSON. During LoginPacket parsing, netresearch/jsonmapper maps JSON arrays or objects onto scalar model properties such as strings without rejecting the type mismatch. No authentication or user interaction is required; the resulting ErrorException terminates the server process.

CVSS severity8.7
High
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in PocketMine-MP before 4.20.5 allows remote attackers to crash the server via malformed LoginPacket JSON. During LoginPacket parsing, netresearch/jsonmapper maps JSON arrays or objects onto scalar model properties such as strings without rejecting the type mismatch. No authentication or user interaction is required; the resulting ErrorException terminates the server process.

The record

CVE
CVE-2023-54393
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/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.

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-20Improper Input Validation
T1499.004Application 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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