Elasticsearch NoBound Recursion Causing Thread Stack Exhaustion (DoS)
CVE-2026-72686 Published on August 13, 2026
Uncontrolled Recursion in Elasticsearch Leading to Denial of Service
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.
Vulnerability Analysis
CVE-2026-72686 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 does not properly control the amount of recursion which takes place, consuming excessive resources, such as allocated memory or the program stack.
CVE-2026-72686 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-72686
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Affected Versions
Elasticsearch:- Version 8.0.0, <= 8.19.19 is affected.
- Version 9.0.0, <= 9.4.4 is affected.
- Version 9.5.0 is affected.