CVE Catalog

CVE-2026-102408

MediumCVSS 4.3
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

25th percentile - higher than 25% of all known CVEs

Summary

Inefficient regular expression complexity in Elasticsearch's ES|QL CHUNK function can lead to denial of service via catastrophic backtracking. A user with read access to a text-based index can submit a crafted regex causing excessive CPU consumption and degrading query throughput for other tenants.

Risk Assessment

The risk involves performance degradation of the Elasticsearch cluster, potentially affecting service availability for other users, though the cluster does not crash.

Recommendation

Upgrade Elasticsearch to a patched version and restrict read access to text-based indices for untrusted users. Monitor CPU usage in the context of ES|QL queries.

Other vulnerabilities in Elasticsearch

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Original NVD description (English source)

Inefficient Regular Expression Complexity (CWE-1333) in Elasticsearch can lead to denial of service via Regular Expression Exponential Blowup (CAPEC-492). The ES|QL CHUNK function's recursive chunking strategy accepts a list of user-supplied regular expressions used as text-splitting separators, without validating their computational complexity or bounding their execution time. An authenticated user with read access to any text-based index can submit a specially crafted regular expression that triggers catastrophic backtracking, consuming excessive CPU on Elasticsearch worker threads and degrading query throughput for other tenants on the affected node. The cluster does not crash as a result of this issue.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS