# CVE-2026-72636

## Summary

- **CVE ID:** CVE-2026-72636
- **Severity:** MEDIUM
- **CVSS Score:** 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-674
- **Published:** Aug 13, 2026
- **Last Modified:** Aug 13, 2026

## Description

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.

## Affected Products

- Elastic — Elasticsearch (8.0.0)
- Elastic — Elasticsearch (9.0.0)

## References

- [CNA](https://discuss.elastic.co/t/elasticsearch-8-19-20-9-4-5-security-update-esa-2026-133/389499)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.30%
- **EPSS Percentile:** 22.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._