TI-2026-45076 Aliases CVE-2026-63140 GHSA-h663-9fgh-w7xf

Reachable Assertion in Elasticsearch Leading to Denial of Service

LOW 29CWE-617Published 2026-07-21 · Updated 2026-07-22

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-617.

Summary

Reachable Assertion (CWE-617) in Elasticsearch can lead to denial of service via Input Data Manipulation (CAPEC-153). A specially crafted search request containing a null value in a specific query clause causes an internal assertion to be raised during query parsing. Because Elasticsearch treats assertion failures as fatal errors, this terminates the affected node process. A low-privileged authenticated user with read access to at least one index can exploit this condition with a single request to cause a node to terminate, disrupting search availability. In a single-node deployment this fully stops Elasticsearch; in a multi-node cluster it reduces cluster capacity for each affected node.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.0042 36th percentileScored 2026-11-07

Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Elastic	Elasticsearch	9.0.0 – 9.3.7; 9.4.0 – 9.4.3; 8.0.0 – 8.19.18	—	No fix listed	CNA

Elasticsearch VendorElastic Affected 9.0.0 – 9.3.7; 9.4.0 – 9.4.3; 8.0.0 – 8.19.18 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:elastic:elasticsearch::::::::	8.0.0 to before 8.19.19; 9.0.0 to before 9.3.8; 9.4.0 to before 9.4.4	Vulnerable	Elastic

cpe:2.3:a:elastic:elasticsearch:*:*:*:*:*:*:*:* Versions 8.0.0 to before 8.19.19; 9.0.0 to before 9.3.8; 9.4.0 to before 9.4.4 Vulnerable ·Elastic

Remediation

No fixed version listed by the sources yet.

Timeline

2026-10-02 Threatist record created from CVE-2026-63140
2026-10-03 Alias added: GHSA-h663-9fgh-w7xf

References

Advisory 1

https://discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-security-update-esa-2026-64/388565

TI-2015-01295 The Groovy scripting engine in Elasticsearch before 1.3.8 and 1.4.x before 1.4.3 allows… KEVCVSS 3.1CRITICAL 9.8
TI-2014-02491 The default configuration in Elasticsearch before 1.2 enables dynamic scripting, which… KEVCVSS 3.1HIGH 8.1
TI-2023-15037 Elasticsearch StackOverflow vulnerability CVSS 3.1HIGH 7.5
TI-2021-05135 Information disclosure in Elasticsearch CVSS 3.1MEDIUM 6.5
TI-2021-05136 All versions of Elastic Cloud Enterprise has the Elasticsearch “anonymous” user enabled… CVSS 3.1HIGH 7.5
TI-2015-04530 Elasticsearch before 1.6.1 allows remote attackers to execute arbitrary code via… CVSS 3.0CRITICAL 9.8

See all 90 →

Sources

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