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Fencer Intel
medium 6.5

CVE-2026-72678 json

Memory Allocation with Excessive Size Value in Elasticsearch Leading to Denial of Service

published 2mo ago modified 2mo ago also BIT-elasticsearch-2026-72678 , EUVD-2026-58252

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

Elasticsearch does not validate a size value taken from a user-supplied input before that value is used to reserve memory for an internal data structure. An authenticated user holding only read privileges can submit a single small crafted request to a product API endpoint that causes the node to attempt an excessively large allocation. The resulting memory exhaustion raises a fatal error that terminates the Elasticsearch node process, causing a denial of service for the affected node and degrading cluster health. The defect is not volumetric, so a single request is sufficient regardless of the heap size configured on the target node.

Patch / fix

  • bitnami elasticsearch 8.19.20, 9.4.5, 9.5.1
  • elastic elasticsearch 8.19.20, 9.4.5, 9.5.1
  • elasticsearch elasticsearch 8.19.20, 9.4.5, 9.5.1
  • org.elasticsearch elasticsearch 8.19.20, 9.4.5, 9.5.1

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-72678 updated cvss 6.5

elasticsearch: Elasticsearch: Denial of Service via excessive memory allocation

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami elasticsearch
>=8.19.0, <8.19.20
>=9.4.0, <9.4.5
>=9.5.0, <9.5.1
8.19.20
9.4.5
9.5.1

Affected products

  • Elastic Elasticsearch

Classification

Weakness
  • CWE-789 Memory Allocation with Excessive Size Value

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.