CVE-2026-86200: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-h5mw-4vcp-gq3w
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CVSS 5.3
CWE-779
Published
Advisory Summary

CVE-2026-86200 is a MODERATE (CVSS 5.3) security vulnerability vulnerability (CWE-779: Logging of Excessive Data) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product logs too much information, making log files hard to process and possibly hindering recovery efforts or forensic analysis after an attack.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-86200 at a Glance

CVE Identifier CVE-2026-86200
GHSA Identifier GHSA-h5mw-4vcp-gq3w
Severity MODERATE
CVSS v3.1 Base Score 5.3
CWE Classification CWE-779: Logging of Excessive Data
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 5.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability Low (A:L)

How to Fix CVE-2026-86200

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-86200, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-779: Logging of Excessive Data, where the product logs too much information, making log files hard to process and possibly hindering recovery efforts or forensic analysis after an attack. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

PocketMine-MP versions before 5.42.1 contain a denial of service vulnerability in the LoginPacket handler that allows remote attackers to flood warning messages by injecting numerous junk properties into the clientData JWT. Attackers can craft malicious login packets with excessive unknown properties to waste server CPU time and degrade performance.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-xp4f-g2cm-rhg7
NVD — CVE-2026-86200 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86200
Security Fix Commit FIX COMMIT
https://github.com/pmmp/PocketMine-MP/commit/c1d4a813fb8c21bfd8b9affd040da864b794df71
www.vulncheck.com/advisories/pocketmi... WEB
https://www.vulncheck.com/advisories/pocketmine-mp-before-5.42.1-logdos-via-loginpacket-clientdata-jwt

Frequently Asked Questions

What is CVE-2026-86200?
CVE-2026-86200 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-779: Logging of Excessive Data.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-86200?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-86200?
CVE-2026-86200 has a CVSS v3.1 base score of 5.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
What CWE is associated with CVE-2026-86200?
CVE-2026-86200 is classified under CWE-779: Logging of Excessive Data (The product logs too much information, making log files hard to process and possibly hindering recovery efforts or forensic analysis after an attack.).
How can I check Maven dependencies for CVE-2026-86200?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h5mw-4vcp-gq3w",
  "modified" : "2026-09-09T15:35:11Z",
  "published" : "2026-09-09T15:35:11Z",
  "aliases" : [ "CVE-2026-86200" ],
  "details" : "PocketMine-MP versions before 5.42.1 contain a denial of service vulnerability in the LoginPacket handler that allows remote attackers to flood warning messages by injecting numerous junk properties into the clientData JWT. Attackers can craft malicious login packets with excessive unknown properties to waste server CPU time and degrade performance.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS: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:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-xp4f-g2cm-rhg7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86200"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pmmp/PocketMine-MP/commit/c1d4a813fb8c21bfd8b9affd040da864b794df71"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/pocketmine-mp-before-5.42.1-logdos-via-loginpacket-clientdata-jwt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-779" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-09T14:17:21Z"
  }
}