CVE-2026-107726
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.38% probability · 32th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Source
- security-advisories@github.com
EPSS moved from 0.4% on 9 October 2026 to 0.4% on 26 October 2026.
References
- https://docs.hazelcast.com/hazelcast/5.7/release-notes/community
- https://docs.hazelcast.com/hazelcast/5.7/release-notes/enterprise
- https://github.com/hazelcast/hazelcast/commit/361979da12f18950c24719db832ca6c5e7c0534f
- https://github.com/hazelcast/hazelcast/releases/tag/v5.7.0
- https://github.com/hazelcast/hazelcast/security/advisories/GHSA-6v25-8wq6-xq4j
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.