CVE-2026-72686 Uncontrolled Recursion in Elasticsearch Leading to Denial of Service
A low-privileged user can cause a denial of service in Elasticsearch by submitting crafted input that triggers uncontrolled recursion and stack exhaustion.
- 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-2026-72686?
CVE-2026-72686 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
A flaw in Elasticsearch allows a low-privileged authenticated user to submit a single request containing a crafted user-supplied input. A specific internal component validates the input using a recursive routine and applies no bound to the length of the value being validated, so the validation causes the thread to exhaust its stack. The resulting fatal error is not handled by the surrounding execution paths and terminates the affected node process, producing a denial of service.
Weakness: CWE-674
Which versions are affected by CVE-2026-72686?
1 open source package ship an affected version, including elasticsearch. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
elasticsearch Bitnami | From 8.0.0 | 8.19.20, 9.4.5, 9.5.1 |
Products include Elastic Elasticsearch.
How do I fix CVE-2026-72686?
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-2026-72686 being exploited?
There is no known exploitation of CVE-2026-72686 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-2026-72686, CLEANSTART-2026-KP61093, CLEANSTART-2026-SM94117, GHSA-qj5v-cq2v-qvgj, MINI-29h7-wh85-fj94, MINI-37vh-78xx-p837 and 19 more.