Quick answers
- Is CVE-2026-102409 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-102409 being exploited in the wild.
- How severe is CVE-2026-102409?
- Medium severity, with a CVSS score of 6.5, published 6 October 2026.
- Which products and versions are affected?
- Elasticsearch 9.2.0–9.2.8, 9.3.0–9.3.8, 9.4.0–9.4.7, 9.5.0–9.5.4.
- Is there a fix for CVE-2026-102409?
- Yes: fixed in Elasticsearch 9.4.8, 9.5.5. Until then: No workarounds are available. Users unable to upgrade immediately should disable ES|QL or restrict index read access to high-privileged users only. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-102409 attacked?
- It is attacked over the network, in a hosted service.
- Am I affected by CVE-2026-102409?
- Check whether you run Elasticsearch at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Elasticsearch 9.4.8, 9.5.5
No workarounds are available. Users unable to upgrade immediately should disable ES|QL or restrict index read access to high-privileged users only.
Technical details
An uncontrolled recursion vulnerability (CWE-674) exists in Elasticsearch's text chunking functionality, introduced in version 9.2.0. When ES|QL is enabled (default configuration), a low-privileged authenticated user can submit a malicious query that triggers excessive recursion, exhausting memory and terminating the node. The vulnerability requires network access and valid credentials but no special privileges.
Affected products
- Elastic Elasticsearch 9.2.0–9.2.8, 9.3.0–9.3.8, 9.4.0–9.4.7, 9.5.0–9.5.4
Timeline
- 2026-10-06: disclosed