Vulnerability in Elastic Elasticsearch
CVE-2026-72636
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (33.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Elastic Elasticsearch — versions 8.0.0, 9.0.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-72636?
- CVE-2026-72636 is a medium-severity vulnerability in Elastic Elasticsearch, classified under Uncontrolled Recursion. CVSS score: 6.5/10. Published 2026-08-13.
- How severe is CVE-2026-72636?
- Medium severity. CVSS v3 base score is 6.5 out of 10.