Elasticsearch Wildcard Matching Recursion Overflow Enables DoS
CVE-2026-72636 Published on August 13, 2026
Uncontrolled Recursion in Elasticsearch Wildcard Matching Leading to Denial of Service
Uncontrolled Recursion (CWE-674) in the Elasticsearch wildcard matching helper can lead to a denial of service via Excessive Allocation (CAPEC-130). The matcher used to resolve wildcard patterns against names is implemented recursively and had no bound on recursion depth or on the total number of match operations performed. A search request containing a wildcard pattern with a large number of wildcard groups, evaluated against a sufficiently long name, exhausts the thread stack. Elasticsearch treats a stack overflow as an unrecoverable condition and shuts the node down, so the request terminates the affected node rather than failing gracefully.
Vulnerability Analysis
CVE-2026-72636 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-2026-72636 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-72636
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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.