What’s Vulnerable › Vulnerabilities
CVE-2026-72636: Uncontrolled Recursion in Elasticsearch Wildcard Matching Leading to Denial of Service
- Severity: medium (CVSS 6.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-13 · updated 2026-09-01
- Weakness: CWE-674
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
- Elasticsearch: from 8.0.0 before 8.19.20; from 9.0.0 before 9.4.5 — fixed in 8.19.20, 9.4.5
How to fix
Upgrade to a fixed version: Elasticsearch 8.19.20, 9.4.5. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-72636 or the next vulnerability affects your stack