Vulnerability-Lookup

GHSA-6V25-8WQ6-XQ4J

Vulnerability from github – Published: 2026-10-08 22:10 – Updated: 2026-10-08 22:10

Summary

Hazelcast allows arbitrary member memory access by low-privileged client

Details

Impact

A flaw has been found in Hazelcast Enterprise Edition and Community Edition, which would allow a low-privileged malicious client to read arbitrary data in memory from any cluster member (including Java heap memory, off-heap data, and JVM process address space). Additionally, such a client may be able to cause one or more cluster members to crash, or in some Enterprise Edition configurations also corrupt memory contents, potentially leading to remote code execution. Both slim and full distributions are affected.

Patches

Enterprise customers should upgrade to a fixed version of Hazelcast Enterprise Edition: * 5.7.0 * 5.6.1 * 5.5.10 * 5.4.5

Customers with extended support contracts should contact Hazelcast Support for information on patches for older versions.

Community Edition users should upgrade to version 5.7.0.

Hazelcast also recommends all customers follow the advice in our Security Hardening guide, including:

Ensure Hazelcast Security is enabled and client authorization is enforced.
Define an explicit allowlist for zero config Compact serialization.
Avoid deploying clients on internet-facing non-secure networks or non-secure hosts.
Ensure your Hazelcast cluster is appropriately protected by firewall rules.
Disable any features you are not using.

Workarounds

If you cannot update to a fixed version immediately, restrict cluster access to trusted clients only and ensure clients are hardened against compromise.

References

Security Advisory on the Hazelcast Support Portal

Severity

9.3 (Critical)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "com.hazelcast:hazelcast"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.6.0"
            },
            {
              "fixed": "5.7.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.6.0"
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 5.5.10"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "com.hazelcast:hazelcast"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.5.0"
            },
            {
              "fixed": "5.7.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c 5.4.5"
      },
      "package": {
        "ecosystem": "Maven",
        "name": "com.hazelcast:hazelcast"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.7.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-107726"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-08T22:10:29Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nA flaw has been found in Hazelcast Enterprise Edition and Community Edition, which would allow a low-privileged malicious client to read arbitrary data in memory from any cluster member (including Java heap memory, off-heap data, and JVM process address space). Additionally, such a client may be able to cause one or more cluster members to crash, or in some Enterprise Edition configurations also corrupt memory contents, potentially leading to remote code execution. Both slim and full distributions are affected.\n\n### Patches\n\nEnterprise customers should upgrade to a fixed version of Hazelcast Enterprise Edition:\n * 5.7.0\n * 5.6.1\n * 5.5.10\n * 5.4.5\n \nCustomers with extended support contracts should contact Hazelcast Support for information on patches for older versions.\n\nCommunity Edition users should upgrade to version 5.7.0.\n\nHazelcast also recommends all customers follow the advice in our [Security Hardening guide](https://docs.hazelcast.com/hazelcast/5.7/secure-cluster/hardening-recommendations), including:\n\n * Ensure [Hazelcast Security](https://docs.hazelcast.com/hazelcast/5.7/security/enable-security) is enabled and [client authorization](https://docs.hazelcast.com/hazelcast/5.7/security/client-authorization) is enforced.\n * Define an [explicit allowlist for zero config Compact serialization](https://docs.hazelcast.com/hazelcast/5.7/serialization/compact-serialization#zero-config-filter).\n * Avoid deploying clients on internet-facing non-secure networks or non-secure hosts.\n * Ensure your Hazelcast cluster is appropriately protected by firewall rules.\n * Disable any features you are not using.\n\n### Workarounds\nIf you cannot update to a fixed version immediately, restrict cluster access to trusted clients only and ensure clients are hardened against compromise.\n\n### References\n\n[Security Advisory on the Hazelcast Support Portal](https://support.hazelcast.com/s/article/Security-Advisory-GHSA-6v25-8wq6-xq4j)",
  "id": "GHSA-6v25-8wq6-xq4j",
  "modified": "2026-10-08T22:10:29Z",
  "published": "2026-10-08T22:10:29Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/hazelcast/hazelcast/security/advisories/GHSA-6v25-8wq6-xq4j"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hazelcast/hazelcast/commit/361979da12f18950c24719db832ca6c5e7c0534f"
    },
    {
      "type": "WEB",
      "url": "https://docs.hazelcast.com/hazelcast/5.7/release-notes/community"
    },
    {
      "type": "WEB",
      "url": "https://docs.hazelcast.com/hazelcast/5.7/release-notes/enterprise"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/hazelcast/hazelcast"
    },
    {
      "type": "WEB",
      "url": "https://github.com/hazelcast/hazelcast/releases/tag/v5.7.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Hazelcast allows arbitrary member memory access by low-privileged client"
}

CVE-2026-107726 (GCVE-0-2026-107726)

Vulnerability from cvelistv5 – Published: 2026-10-08 22:08 – Updated: 2026-10-09 15:12

Title

Hazelcast: Arbitrary member memory access by low-privileged client

Summary

Hazelcast is a unified real-time data platform combining stream processing with a fast data store. Prior to 5.4.5, 5.5.10, and 5.6.1, improper validation of data supplied by a malicious client able to connect to a cluster allows arbitrary reads from a cluster member's Java heap, off-heap data, and JVM process address space. The same flaw can crash cluster members and, in some Hazelcast Enterprise Edition configurations, corrupt memory with possible arbitrary code execution. Both slim and full distributions are affected. This issue is fixed in versions 5.4.5, 5.5.10, 5.6.1, and 5.7.0.

Severity

9.3 (Critical)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-09 15:07 UTC

CWE

CWE-20 - Improper Input Validation

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7638 records in the last 180 days details

References

5 references

URL	Tags
https://github.com/hazelcast/hazelcast/security/a…	x_refsource_CONFIRM
https://github.com/hazelcast/hazelcast/commit/361…	x_refsource_MISC
https://docs.hazelcast.com/hazelcast/5.7/release-…	x_refsource_MISC
https://docs.hazelcast.com/hazelcast/5.7/release-…	x_refsource_MISC
https://github.com/hazelcast/hazelcast/releases/t…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
hazelcast	hazelcast	Affected: < 5.4.5 Affected: >= 5.5.0, < 5.5.10 Affected: >= 5.6.0, < 5.6.1

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JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-107726",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-09T15:07:22.266395Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-09T15:12:52.740Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "hazelcast",
          "vendor": "hazelcast",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.4.5"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.5.0, \u003c 5.5.10"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.6.0, \u003c 5.6.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Hazelcast is a unified real-time data platform combining stream processing with a fast data store. Prior to 5.4.5, 5.5.10, and 5.6.1, improper validation of data supplied by a malicious client able to connect to a cluster allows arbitrary reads from a cluster member\u0027s Java heap, off-heap data, and JVM process address space. The same flaw can crash cluster members and, in some Hazelcast Enterprise Edition configurations, corrupt memory with possible arbitrary code execution. Both slim and full distributions are affected. This issue is fixed in versions 5.4.5, 5.5.10, 5.6.1, and 5.7.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
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          "descriptions": [
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              "lang": "en",
              "type": "CWE"
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-08T22:08:09.553Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/hazelcast/hazelcast/security/advisories/GHSA-6v25-8wq6-xq4j",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/hazelcast/hazelcast/security/advisories/GHSA-6v25-8wq6-xq4j"
        },
        {
          "name": "https://github.com/hazelcast/hazelcast/commit/361979da12f18950c24719db832ca6c5e7c0534f",
          "tags": [
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          "url": "https://github.com/hazelcast/hazelcast/commit/361979da12f18950c24719db832ca6c5e7c0534f"
        },
        {
          "name": "https://docs.hazelcast.com/hazelcast/5.7/release-notes/community",
          "tags": [
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          "url": "https://docs.hazelcast.com/hazelcast/5.7/release-notes/community"
        },
        {
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          "tags": [
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          "url": "https://docs.hazelcast.com/hazelcast/5.7/release-notes/enterprise"
        },
        {
          "name": "https://github.com/hazelcast/hazelcast/releases/tag/v5.7.0",
          "tags": [
            "x_refsource_MISC"
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          "url": "https://github.com/hazelcast/hazelcast/releases/tag/v5.7.0"
        }
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      "source": {
        "advisory": "GHSA-6v25-8wq6-xq4j",
        "discovery": "UNKNOWN"
      },
      "title": "Hazelcast: Arbitrary member memory access by low-privileged client"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-107726",
    "datePublished": "2026-10-08T22:08:09.553Z",
    "dateReserved": "2026-10-08T17:21:52.976Z",
    "dateUpdated": "2026-10-09T15:12:52.740Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

GHSA-6V25-8WQ6-XQ4J

Impact

Patches

Workarounds

References

CVE-2026-107726 (GCVE-0-2026-107726)

Tags

Sightings

Nomenclature

Related by attack behaviour