CVE-2026-86204

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-09. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this weekElevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

PocketMine-MP versions before 5.39.2 fail to limit JSON payload size in ModalFormResponsePacket handling, allowing authenticated players to cause denial of service. Attackers can send modal form response packets with massive JSON arrays to exhaust server memory and CPU resources, rendering the server unresponsive.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
45(Track)
EG Risk 45/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

September 9, 2026

Last Modified

September 9, 2026

Advisory Details (2)

Auto-updated Sep 9, 2026
🔬 Proof of concept available. Patch available. Sources: github.
generic

PocketMine-MP before 5.39.2 Denial of Service via ModalFormResponsePacket | Advisories | VulnCheck

https://www.vulncheck.com/advisories/pocketmine-mp-before-5.39.2-denial-of-service-via-modalformresponsepacket
github Patch Available🟡 PoC Available

JSON decoding of unlimited size large arrays/objects in ModalFormResponse Handling · Advisory · pmmp/PocketMine-MP · GitHub

https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-788v-5pfp-93ff

Vendor Advisories for CVE-2026-86204(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFixed inDependents
pocketmine/pocketmine-mp3.0.0 ... 5.9.0 (377 versions)5.39.2—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 09:45 UTCEG score recompute
  3. 2026-09-18 09:45 UTCGHSA enrichment
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-17 08:08 UTCEG score recompute
  6. 2026-09-17 08:08 UTCGHSA enrichment
  7. 2026-09-16 14:09 UTCEPSS rescore
  8. 2026-09-16 06:31 UTCEG score recompute
  9. 2026-09-16 06:31 UTCGHSA enrichment
  10. 2026-09-16 05:15 UTCEPSS rescore
  11. 2026-09-15 04:54 UTCEG score recompute
  12. 2026-09-15 04:53 UTCGHSA enrichment
  13. 2026-09-15 03:12 UTCEPSS rescore
  14. 2026-09-15 03:12 UTCEPSS rescore
  15. 2026-09-14 03:12 UTCEG score recompute
  16. 2026-09-14 03:12 UTCGHSA enrichment
  17. 2026-09-13 01:35 UTCEG score recompute
  18. 2026-09-13 01:35 UTCGHSA enrichment
  19. 2026-09-11 23:58 UTCEG score recompute
  20. 2026-09-11 23:58 UTCGHSA enrichment
  21. 2026-09-11 14:53 UTCEPSS rescore
  22. 2026-09-11 14:53 UTCEPSS rescore
  23. 2026-09-10 22:20 UTCGHSA enrichment
  24. 2026-09-09 20:41 UTCEG score recompute
  25. 2026-09-09 20:41 UTCGHSA enrichment
Show 4 more
  1. 2026-09-09 15:29 UTCEG score recompute
  2. 2026-09-09 14:27 UTCEG score recompute
  3. 2026-09-09 13:45 UTCEG score recompute
  4. 2026-09-09 13:44 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86204?
CVE-2026-86204 is a medium vulnerability published on September 9, 2026. PocketMine-MP versions before 5.39.2 fail to limit JSON payload size in ModalFormResponsePacket handling, allowing authenticated players to cause denial of service. Attackers can send modal form response packets with massive JSON arrays to exhaust server memory and CPU resources, rendering the…
When was CVE-2026-86204 disclosed?
CVE-2026-86204 was first published in the National Vulnerability Database on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86204 actively exploited?
CVE-2026-86204 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 69.1% of all scored CVEs.
What is the CVSS score of CVE-2026-86204?
CVE-2026-86204 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-86204?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86204, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-86204

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