CVE-2026-102408

Summary

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.

Affected Software

VendorProductVersion RangeStatus
ElasticElasticsearch8.19.0 <= 8.19.21affected
ElasticElasticsearch9.1.0 <= 9.3.8affected
ElasticElasticsearch9.4.0 <= 9.4.7affected
ElasticElasticsearch9.5.0 <= 9.5.4affected

Weaknesses

  • CWE-1333: CWE-1333 Inefficient Regular Expression Complexity

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References