CVE-2026-102411
Description
A flaw was found in Elasticsearch. An authenticated user with index template management privileges can cause a Denial of Service (DoS) by registering multiple template resources and requesting them together. Although size limits exist for individual metadata entries, the system does not restrict cumulative memory consumption when retrieving multiple resources at once. This can exhaust available memory and cause the affected node to crash.
Statement
A moderate-impact denial of service vulnerability was found in Elasticsearch. An authenticated user who holds the manage_index_templates cluster privilege can register multiple index template resources whose user-supplied metadata each stay within the enforced per-resource size limit. When multiple such resources are retrieved together, Elasticsearch does not limit the total memory used to materialize their metadata values, so the combined retrieval can exhaust the node's available heap and cause the affected node to fail with an out-of-memory error, resulting in a denial of service. The flaw affects availability only, with no impact on confidentiality or integrity, and the Red Hat severity matches the upstream assessment (CVSS 3.1 score 6.5, CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, Moderate). In Red Hat's scope, this flaw affects the community offerings for Elasticsearch (the Fedora and EPEL streams), which are tracked as affected, and a fix is being pursued for those streams.
Mitigation
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. The upstream Elastic advisory states that there are no workarounds for this vulnerability and that the issue is resolved in Elasticsearch 9.4.7, 9.5.3, and 8.19.23; Elastic recommends upgrading to the most recent release available.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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