Answer in brief
CVE-2026-102408 records a Medium severity (CVSS 4.3) vulnerability in Inefficient Regular Expression Complexity in Elasticsearch Leading to Denial of Service. The current sources do not mark it as known exploited. The current feed maps Elastic/Elasticsearch (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 4.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Elastic/Elasticsearch (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Elastic/Elasticsearchgeneric | >=8.19.0 <=8.19.21 || >=9.1.0 <=9.3.8 || >=9.4.0 <=9.4.7 || >=9.5.0 <=9.5.4 | Not reported |
Published upstream
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.