# CVE-2026-107726: Hazelcast: Arbitrary member memory access by low-privileged client

> A malicious client can read arbitrary memory, crash cluster members, or potentially execute code via memory corruption in Hazelcast.

- **Severity:** Critical 9.3 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Oct 2026
- **Updated:** 9 Oct 2026
- **Also known as:** CLEANSTART-2026-JE76711, GHSA-6v25-8wq6-xq4j, MINI-4f96-hgw5-pvqv, MINI-fmg6-59ph-qc99, ROOT-APP-MAVEN-CVE-2026-107726

## What is CVE-2026-107726?

CVE-2026-107726 is a critical memory corruption vulnerability in hazelcast, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2026-107726?

6 open source packages ship an affected version, including com.hazelcast:hazelcast.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `com.hazelcast:hazelcast` | Maven | All versions | 5.7.0 |
| `com.hazelcast:hazelcast` | Maven | All versions | 5.7.0 |
| `com.hazelcast:hazelcast` | Maven | From 5.5.0 | 5.7.0 |
| `com.hazelcast:hazelcast` | Maven | From 5.5.0 | 5.7.0 |
| `com.hazelcast:hazelcast` | Maven | From 5.6.0 | 5.7.0 |
| `com.hazelcast:hazelcast` | Maven | From 5.6.0 | 5.7.0 |

## How do I fix CVE-2026-107726?

Upgrade com.hazelcast:hazelcast to 5.7.0 or later.

## Is CVE-2026-107726 being exploited?

There is no known exploitation of CVE-2026-107726 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-107726 and fix it if it is affected.

What it is: CVE-2026-107726 is a critical memory corruption vulnerability in hazelcast, published on 8 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-107726 in the wild and no public exploit code.

Affected packages and fixed versions:
- com.hazelcast:hazelcast (Maven): affected all versions; fixed in 5.7.0
- com.hazelcast:hazelcast (Maven): affected all versions; fixed in 5.7.0
- com.hazelcast:hazelcast (Maven): affected from 5.5.0; fixed in 5.7.0
- com.hazelcast:hazelcast (Maven): affected from 5.5.0; fixed in 5.7.0
- com.hazelcast:hazelcast (Maven): affected from 5.6.0; fixed in 5.7.0
- com.hazelcast:hazelcast (Maven): affected from 5.6.0; fixed in 5.7.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-107726/ (Markdown: https://insights.sbomify.com/CVE-2026-107726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-107726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-107726
- OSV: https://osv.dev/vulnerability/CVE-2026-107726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-107726/
Summaries are generated and may contain mistakes; the official description above is the record.