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Vulnerabilities

Vulnerability · CVE-2026-107726

Hazelcast allows arbitrary member memory access by low-privileged client

Published Oct 8, 2026 · catalog updated Oct 8, 2026 · Hazelcast allows arbitrary member

Check if you run it

No confirmed exploitation is on record for CVE-2026-107726. EPSS is 0.38%. Act only if a listed version of Hazelcast allows arbitrary member is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Hazelcast allows arbitrary member).
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Critical—
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.38%
Remediation
Advisory link
Affected products
Maven com.hazelcast:hazelcast

### 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](https://docs.hazelcast.com/hazelcast/5.7/secure-cluster/hardening-recommendations), including: * 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. * Define an [explicit allowlist for zero config Compact serialization](https://docs.hazelcast.com/hazelcast/5.7/serialization/compact-serialization#zero-config-filter). * 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](https://support.hazelcast.com/s/article/Security-Advisory-GHSA-6v25-8wq6-xq4j)

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • Maven com.hazelcast:hazelcast0 → 5.7.0
  • Maven com.hazelcast:hazelcast5.5.0 → 5.7.0
  • Maven com.hazelcast:hazelcast5.6.0 → 5.7.0

How to fix CVE-2026-107726

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-107726. EPSS is 0.38%. Act only if a listed version of Hazelcast allows arbitrary member is installed.

Which versions are affected?

Compare what you have installed with 0 → 5.7.0, 5.5.0 → 5.7.0, 5.6.0 → 5.7.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-20: Improper Input Validation. EPSS 0.38%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 8, 2026 · Catalog

    Detected

    ### 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 configurat

  2. Oct 8, 2026 · Catalog

    Fix available

    Maven com.hazelcast:hazelcast 5.6.0 → 5.7.0

  3. Oct 8, 2026 · Catalog

    Fix available

    Maven com.hazelcast:hazelcast 5.5.0 → 5.7.0

  4. Oct 8, 2026 · Catalog

    Fix available

    Maven com.hazelcast:hazelcast 0 → 5.7.0

  5. Oct 8, 2026 · GitHub Advisory Database

    Fix available

    com.hazelcast:hazelcast fixed in 5.7.0; com.hazelcast:hazelcast fixed in 5.7.0; com.hazelcast:hazelcast fixed in 5.7.0

  6. Oct 8, 2026 · GitHub Advisory Database

    Fix available

    com.hazelcast:hazelcast fixed in 5.7.0

  7. Oct 8, 2026 · Catalog

    Updated

    ### 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 configurat

Sources

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.