Elasticsearch ES|QL Excessive Heap Allocation DoS
CVE-2026-72656 Published on August 13, 2026
Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service
Memory Allocation with Excessive Size Value (CWE-789) in the ES|QL query processing of Elasticsearch can lead to denial of service via Excessive Allocation (CAPEC-130). An authenticated user able to submit ES|QL queries could send a specially crafted query whose evaluation allocates an unbounded amount of heap memory, exhausting the available heap on the receiving node and causing the node to become unavailable.
Vulnerability Analysis
CVE-2026-72656 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Stack Exhaustion Vulnerability?
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
CVE-2026-72656 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-72656
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Affected Versions
Elasticsearch:- Version 8.11.0, <= 8.17.9 is affected.