Summary
PocketMine-MP has improperly handled dye colour IDs in banner NBT, leading to server crash
Workarounds
This is quite difficult to work around via a plugin. Theoretically, it's possible to override the Banner item class from a plugin and validate the data before it reaches deserializeCompoundTag().
For more information
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Impact
DyeColorIdMap->fromId() did not account for the possibility that it might be given invalid input. This means that an undefined offset error would occur whenever this happened.
This code is indirectly called during Banner->deserializeCompoundTag(), which is invoked when deserializing any item NBT, whether from network or disk.
An attacker could use this bug to crash a server by providing NBT with invalid values for pattern colours in an inventory transaction, or by using /give to obtain an item with NBT like this.
GHSA-WQQV-JCFR-9F5G has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.8.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-WQQV-JCFR-9F5G? GHSA-WQQV-JCFR-9F5G is a high-severity security vulnerability in pocketmine/pocketmine-mp (composer), affecting versions < 4.8.1. It is fixed in 4.8.1.
- How severe is GHSA-WQQV-JCFR-9F5G? GHSA-WQQV-JCFR-9F5G has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pocketmine/pocketmine-mp are affected by GHSA-WQQV-JCFR-9F5G? pocketmine/pocketmine-mp (composer) versions < 4.8.1 is affected.
- Is there a fix for GHSA-WQQV-JCFR-9F5G? Yes. GHSA-WQQV-JCFR-9F5G is fixed in 4.8.1. Upgrade to this version or later.
- Is GHSA-WQQV-JCFR-9F5G exploitable, and should I be worried? Whether GHSA-WQQV-JCFR-9F5G is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-WQQV-JCFR-9F5G is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-WQQV-JCFR-9F5G? Upgrade
pocketmine/pocketmine-mpto 4.8.1 or later.