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Fencer Intel
medium 6.5

CVE-2026-72639 json

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

published 2mo ago modified 2mo ago also BIT-elasticsearch-2026-72639 , EUVD-2026-58285

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 36%
public exploits
0
none known

Summary

Elasticsearch does not enforce an upper bound on a user-supplied count accepted by a search highlighting option, and the allocation derived from that count is not accounted against any circuit breaker. An authenticated user holding only read privileges on a single searchable index can submit one small search request that causes the node to reserve an excessively large internal data structure. The allocation occurs before the existing highlighting safety limits are evaluated, so memory exhaustion raises a fatal error that terminates the Elasticsearch node process. This results in a denial of service for the affected node and degrades cluster routing and health. The defect is not volumetric and does not depend on the size of the indexed data, so a single request is sufficient.

Patch / fix

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

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.42% chance of exploitation in the next 30 days, higher than 36% 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
>=9.3.0, <9.5.1
8.19.20
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.