Vulnerability Description
Elasticsearch does not enforce an upper bound on a user-supplied count accepted by a search highlighting option, and the allocation derived from that count is not accounted against any circuit breaker. An authenticated user holding only read privileges on a single searchable index can submit one small search request that causes the node to reserve an excessively large internal data structure. The allocation occurs before the existing highlighting safety limits are evaluated, so memory exhaustion raises a fatal error that terminates the Elasticsearch node process. This results in a denial of service for the affected node and degrades cluster routing and health. The defect is not volumetric and does not depend on the size of the indexed data, so a single request is sufficient.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Elastic | Elasticsearch | >= 8.19.0, < 8.19.20 |
Related Weaknesses (CWE)
References
FAQ
What is CVE-2026-72639?
CVE-2026-72639 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Elasticsearch does not enforce an upper bound on a user-supplied count accepted by a search highlighting option, and the allocation derived from that count is not accounted against any circuit breaker...
How severe is CVE-2026-72639?
CVE-2026-72639 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-72639?
Check the references section above for vendor advisories and patch information. Affected products include: Elastic Elasticsearch.