CVE-2026-72678 Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service
An authenticated user with read privileges can cause a denial of service by submitting a crafted request that triggers excessive memory allocation, crashing the Elasticsearch node.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-72678?
CVE-2026-72678 is a medium-severity denial of service vulnerability in Elastic Elasticsearch, published on 13 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Elasticsearch does not validate a size value taken from a user-supplied input before that value is used to reserve memory for an internal data structure. An authenticated user holding only read privileges can submit a single small crafted request to a product API endpoint that causes the node to attempt an excessively large allocation. The resulting memory exhaustion raises a fatal error that terminates the Elasticsearch node process, causing a denial of service for the affected node and degrading cluster health. The defect is not volumetric, so a single request is sufficient regardless of the heap size configured on the target node.
Weakness: CWE-789
Which versions are affected by CVE-2026-72678?
1 open source package ship an affected version, including elasticsearch. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
elasticsearch Bitnami | From 8.19.0 | 8.19.20, 9.4.5, 9.5.1 |
Products include Elastic Elasticsearch.
How do I fix CVE-2026-72678?
Upgrade elasticsearch to a fixed version for your release line: 8.19.20, 9.4.5 or 9.5.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-72678 being exploited?
There is no known exploitation of CVE-2026-72678 in the wild and no public exploit code.
Other vulnerabilities in Elastic Elasticsearch
- CVE-2015-1427 Elasticsearch Groovy Scripting Engine Remote Code Execution
- CVE-2014-3120 Elasticsearch Remote Code Execution
- CVE-2015-5377 Code injection in n/a
- CVE-2026-72649 Deserialization of Untrusted Data in Elasticsearch Leading to Remote Code Execution
- CVE-2026-72642 Use of Out-of-range Pointer Offset in the Elasticsearch Machine Learning Native Inference Process
Sources
Also known as BIT-elasticsearch-2026-72678, CLEANSTART-2026-BW82923, CLEANSTART-2026-OE13430, GHSA-wv4v-8jh9-247v, MINI-62mm-9gwj-vg6x, MINI-7vmv-g887-rxjp and 5 more.