CVE-2026-102408
MEDIUM 4.3Inefficient 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.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 28th percentile
Impact if exploited
4.3CVSS 3.1 · MEDIUM
- ConfidentialityNone
- IntegrityNone
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires a low-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
Search for new PoCs
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Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Data snapshot:
Weakness (CWE)
- CWE-1333: Inefficient Regular Expression Complexity
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
References and research data (JSON)
Vendor product assessments
rhoai/odh-feature-server-rhel9 as a component of Red Hat OpenShift AI (RHOAI) · known affected
Vendor assessment for this product only.
pkg:oci/odh-feature-server-rhel9?repository_url=registry.redhat.io/rhoai/odh-feature-server-rhel9
- workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
- none available: Fix deferred
quay/quay-rhel8 as a component of Red Hat Quay 3 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:oci/quay-rhel8?repository_url=registry.redhat.io/quay/quay-rhel8
Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00quay/quay-rhel9 as a component of Red Hat Quay 3 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:oci/quay-rhel9?repository_url=registry.redhat.io/quay/quay-rhel9
Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Elastic | Elasticsearch | ≥ 8.19.0 and < 8.19.22 |
| Elastic | Elasticsearch | ≥ 9.1.0 and < 9.4.8 |
| Elastic | Elasticsearch | ≥ 9.5.0 and < 9.5.5 |
All CVSS metrics
- MEDIUM 4.3 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L - MEDIUM 4.3 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
References
Advisories
- https://discuss.elastic.co/t/elasticsearch-8-19-22-9-4-8-and-9-5-5-security-update-esa-2026-189/390862 CVE record · elastic · Updated 2026-10-06T19:31:39.196Z
NVD · CVE-2026-102408 · Updated 2026-10-13T18:48:04.190
Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00 - https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-102408.json Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-93929 EUVD · EUVD-2026-93929
Technical & other
- https://access.redhat.com/security/cve/CVE-2026-102408 Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2547111 Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-102408 Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-102408 Red Hat · CVE-2026-102408 · Updated 2026-10-08T06:48:41+00:00