← Back to CVE Explorer

CVE-2026-42188

Full vulnerability record from the local CVENow database.

Description

Geyser is a bridge between Minecraft: Bedrock Edition and Minecraft: Java Edition. Prior to 2.9.3, a server-side request forgery (SSRF) vulnerability exists in Geyser’s handling of Bedrock player head texture data. By supplying a crafted Base64-encoded skin texture URL via the /give command, an attacker can cause the Minecraft server to issue arbitrary HTTP GET requests to attacker-controlled or internal endpoints. This occurs server-side, without proper URL validation, and can be triggered by a Bedrock client. This vulnerability is fixed in 2.9.3.

Severity
MEDIUM
CVSS score
4.3 (v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-05-11 22:22:11.277000
Last modified
2026-10-26 18:10:00.173000
View original CVE JSON
{
  "id": "CVE-2026-42188",
  "sourceIdentifier": "[email protected]",
  "published": "2026-05-11T22:22:11.277",
  "lastModified": "2026-10-26T18:10:00.173",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Geyser is a bridge between Minecraft: Bedrock Edition and Minecraft: Java Edition. Prior to 2.9.3, a server-side request forgery (SSRF) vulnerability exists in Geyser’s handling of Bedrock player head texture data. By supplying a crafted Base64-encoded skin texture URL via the /give command, an attacker can cause the Minecraft server to issue arbitrary HTTP GET requests to attacker-controlled or internal endpoints. This occurs server-side, without proper URL validation, and can be triggered by a Bedrock client. This vulnerability is fixed in 2.9.3."
    },
    {
      "lang": "es",
      "value": "Geyser es un puente entre Minecraft: Bedrock Edition y Minecraft: Java Edition. Antes de la 2.9.3, existe una vulnerabilidad de falsificación de petición del lado del servidor (SSRF) en el manejo de Geyser de los datos de textura de la cabeza del jugador de Bedrock. Al proporcionar una URL de textura de skin codificada en Base64 manipulada a través del comando /give, un atacante puede hacer que el servidor de Minecraft emita peticiones GET HTTP arbitrarias a puntos finales controlados por el atacante o internos. Esto ocurre del lado del servidor, sin una validación de URL adecuada, y puede ser activado por un cliente de Bedrock. Esta vulnerabilidad está corregida en la 2.9.3."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "GeyserMC",
          "product": "Geyser",
          "versions": [
            {
              "version": "< 2.9.3",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:N/A:N",
          "baseScore": 2.4,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "HIGH",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 0.9,
        "impactScore": 1.4
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-05-13T14:06:05.950736Z",
          "id": "CVE-2026-42188",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:geysermc:geyser:*:*:*:*:*:*:*:*",
              "versionEndExcluding": "2.9.3",
              "matchCriteriaId": "78C01578-7BAB-41D9-B09A-DA6AF76629B7"
            }
          ]
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/GeyserMC/Geyser/security/advisories/GHSA-xcfg-fcr5-gw9r",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://github.com/GeyserMC/Geyser/security/advisories/GHSA-xcfg-fcr5-gw9r",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ]
    }
  ]
}