PocketMine-MP before 4.2.9 Denial of Service via NBT Deserialization
PocketMine-MP versions before 4.2.9 fail to properly validate NBT data types during deserialization of inventory transaction packets from clients. Attackers can send crafted inventory transactions with malformed NBT tags to trigger server crashes and cause denial of service.
- Published
- Sep 7, 2026
- Updated
- Sep 8, 2026
- EPSS
- 0.5% · 41th percentile
- CWE
- CWE-20
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Report tools
Action score
28
Monitor
Low priority for now.
- CVSS
- 28 / 40 · 7.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · VulnCheck
- 7.1
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
—
Versions reported by the vendor
Affected version ranges reported by the assigning authority (VulnCheck). Independent of NVD's CPE analysis and usually ahead of it.
pmmp PocketMine-MP
- 4.2.9not affected
- before 4.2.9affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Packagist | pocketmine/pocketmine-mp | before 4.2.9 | 4.2.9 |
Same product
pmmp: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-54393PocketMine-MP before 4.20.5 Denial of Service via LoginPacket34Monitor
- CVE-2023-54390PocketMine-MP before 5.3.1 Denial of Service via LoginPacket34Monitor
- CVE-2023-54355PocketMine-MP 5.2.0 Server Crash via Incorrect EC Curve34Monitor
- CVE-2026-86201PocketMine-MP before 5.41.1 LogDoS via LoginPacket clientData34Monitor
- CVE-2026-86199PocketMine-MP before 5.43.1 Denial of Service via unauthenticated login34Monitor
- CVE-2024-58381PocketMine-MP before 5.11.1 Denial of Service via LoginPacket34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| pmmp PocketMine-MP | 4.2.9 | Vendor (CNA) |
| Packagist:pocketmine/pocketmine-mp | 4.2.9 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2022-510170 days apartPocketMine-MP before 3.26.5 and 4.0.5 Denial of Service via Skin Data34Monitor
- CVE-2023-543932 days apartPocketMine-MP before 4.20.5 Denial of Service via LoginPacket34Monitor
- CVE-2022-510130 days apartPocketMine-MP before 4.2.3 Denial of Service via NBT Metadata28Monitor
- CVE-2022-510150 days apartPocketMine-MP before 4.0.6 Denial of Service via PlayerActionPacket28Monitor
- CVE-2022-510100 days apartPocketMine-MP before 4.4.2 Server Crash via Item ID28Monitor
- CVE-2021-480071 days apartPocketMine-MP before 3.18.1 Denial of Service via MovePlayerPacket28Monitor
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2022-510160 days apartPocketMine-MP 3.x before 3.27.0 Authentication Bypass via Login Replay21Monitor
- CVE-2023-543942 days apartPocketMine-MP before 4.18.0-ALPHA2 Bandwidth Amplification via InventoryTransactionPacket21Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/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
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/pmmp/PocketMine-MP/commit/5a98b08ee8dc8ff14862cd83d2e4af9d212fefc2
- github.com/pmmp/PocketMine-MP/security/advisories/GHSA-g5rr-p69h-7v3g
- www.vulncheck.com/advisories/pocketmine-mp-before-4.2.9-denial-of-service-via-nbt-deserialization
Vendor advisories and official records. Exploit/PoC links are deliberately left out.