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Medium

PocketMine-MP vulnerable to denial-of-service by sending large modal form responses

  • Disclosed: 10.01.2023
  • Updated: 11.10.2026 10:22

Impact

Due to a workaround for an old client bug (which has since been fixed), very large JSON payloads in ModalFormResponsePacket were able to cause the server to spend a significant amount of time processing the packet. Large numbers of these packets were able to hog CPU time so as to prevent the server from processing other connections in a timely manner.

Patches

The problem has been addressed in 3baa5ab71214f96e6e7ab12cb9beef08118473b5 by removing the workaround code.

Workarounds

Plugins could cancel DataPacketReceiveEvent for this packet, decode the data their way, and then call Player->onFormSubmit() directly, bypassing the vulnerable code.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package pocketmine/pocketmine-mp < 4.12.5 4.12.5

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
-
Platform
Composer
Package
pocketmine/pocketmine-mp
Disclosed
10.01.2023
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-7m9r-rq9j-wmmh - CC BY 4.0

Vulnerability history: pocketmine/pocketmine-mp

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (30) in the archive
Total entries
30
First → latest
11.2020 04.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 20
  • Medium 8
  • Low 2

Disclosures per year

Severity:
  1. PocketMine-MP: JSON decoding of unlimited size large arrays/objects in ModalFormResponse Handling
    High CVE-2026-86204 < 5.39.2 5.39.2
  2. PocketMine-MP: LogDoS by large complex unknown property logging in clientData in LoginPacket
    High · 7.5 CVE-2026-86201 < 5.41.1 5.41.1
  3. PocketMine-MP `ResourcePackDataInfoPacket` amplification vulnerability due to lack of resource pack sequence status checking
    High CVE-2025-71417 < 5.32.1 5.32.1
  4. PocketMine-MP server crash with certain invalid JSON payloads in `LoginPacket` due to dependency vulnerability (3rd time)
    High · 7.5 CVE-2024-58381 < 5.11.1 5.11.1
  5. PocketMine-MP BookEditPacket crash when inventory slot in the packet is invalid
    High · 7.5 CVE-2024-58380 < 5.11.2 5.11.2
  6. PocketMine-MP server crash with certain invalid JSON payloads in `LoginPacket` due to dependency vulnerability (again)
    High · 7.5 CVE-2023-54390 >= 5.0.0, < 5.3.1, < 4.23.1 5.3.1, 4.23.1
  7. PocketMine-MP server crash due to incorrect EC curve used for LoginPacket identityPublicKey
    High · 7.5 CVE-2023-54355 >= 5.2.0, < 5.3.1 5.3.1
  8. PocketMine-MP vulnerable to server crash using badly formatted sign NBT in BlockActorDataPacket
    High · 7.5 CVE-2023-54392 >= 4.20.0, < 4.22.3, >= 5.0.0, < 5.2.1 4.22.3, 5.2.1
  9. PocketMine-MP vulnerable to improperly checked dropped item count leading to server crash
    High · 7.5 CVE-2023-7332 < 4.18.1 4.18.1
  10. PocketMine-MP vulnerable to server crash with certain invalid JSON payloads in `LoginPacket` due to vulnerable dependency
    High · 7.5 CVE-2023-54393 < 4.20.5, >= 4.21.0, < 4.21.1 4.20.5, 4.21.1
  11. PocketMine-MP vulnerable to denial-of-service by sending large modal form responses this entry
    Medium · 5.3 CVE-2023-54395 < 4.12.5 4.12.5
  12. PocketMine-MP has improperly handled dye colour IDs in banner NBT, leading to server crash
    High · 7.5 CVE-2023-54396 < 4.8.1 4.8.1
  13. PocketMine-MP invalid skin geometry JSON data leading to server crash
    High · 7.5 CVE-2022-51009 < 4.7.2 4.7.2
  14. Improperly checked IDs on itemstacks received from the client leading to server crash in PocketMine-MP
    High · 7.5 CVE-2022-51010 >= 4.0.0-BETA5, < 4.4.2 4.4.2
  15. Insufficient type validation in pocketmine/pocketmine-mp
    High · 7.5 CVE-2022-51012 < 4.2.9 4.2.9
  16. Improperly checked metadata on tools/armour itemstacks received from the client
    High · 7.5 CVE-2022-51013 < 4.2.4 4.2.4
  17. NaN/INF in serverbound movement packets can crash clients and servers
    High · 7.5 CVE-2021-48007 < 3.18.1 3.18.1
  18. Unhandled exception when decoding form response JSON
    High · 7.5 CVE-2022-51014 >= 4.0.0, < 4.0.7 4.0.7
  19. Unchecked validity of Facing values in PlayerActionPacket
    High · 7.5 CVE-2022-51015 < 4.0.6 4.0.6
  20. Uncapped length of skin data fields submitted by players
    High · 7.5 CVE-2022-51017 < 3.26.5, >= 4.0.0, < 4.0.5 3.26.5, 4.0.5
  21. Exploitable inventory component chaining in PocketMine-MP
    High CVE-2020-37277 < 3.15.4 3.15.4

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