Is CVE-2026-78607 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-78607 being exploited in the wild.

How severe is CVE-2026-78607?

Medium severity, with a CVSS score of 5.4, published 1 September 2026.

Which products and versions are affected?

Elasticsearch 8.0.0–8.19.18, 9.0.0–9.3.7, 9.4.0–9.4.3, 9.5.0.

Is there a fix for CVE-2026-78607?

A patch was published on 2026-09-01: Patches released in versions 8.19.19, 9.3.8, 9.4.4, 9.5.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-78607 attacked?

It is attacked over the network.

Am I affected by CVE-2026-78607?

Check whether you run Elasticsearch at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-78607: Elastic Elasticsearch missing authorization in custom inference service

CVE-2026-78607 · Severity: medium · CVSS 5.4 · Published 2026-09-01

Elasticsearch, a widely-used search and analytics platform, contains a missing authorization flaw in its custom inference service that can be exploited by users with basic inference execution privileges. An attacker with these limited permissions could redirect inference traffic to attacker-controlled servers and extract administrator-provisioned credentials, leading to credential exposure and potential further compromise of the system.

Technologies: Elasticsearch. Vendors: Elastic.

Quick answers

Is CVE-2026-78607 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-78607 being exploited in the wild.
How severe is CVE-2026-78607?: Medium severity, with a CVSS score of 5.4, published 1 September 2026.
Which products and versions are affected?: Elasticsearch 8.0.0–8.19.18, 9.0.0–9.3.7, 9.4.0–9.4.3, 9.5.0.
Is there a fix for CVE-2026-78607?: A patch was published on 2026-09-01: Patches released in versions 8.19.19, 9.3.8, 9.4.4, 9.5.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-78607 attacked?: It is attacked over the network.
Am I affected by CVE-2026-78607?: Check whether you run Elasticsearch at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is a missing authorization check (CWE-862) in the Elasticsearch custom inference service component. Users holding only inference execution privileges can manipulate the inference service to redirect outbound traffic to destinations of their choosing and expose credentials provisioned by administrators. The flaw requires the deployment to use the custom inference service type with secret-backed configuration and requires the attacker to have inference execution privileges. The attack is network-reachable and requires only valid low-privilege user credentials. Patches are available in Elasticsearch versions 8.19.19, 9.3.8, 9.4.4, and 9.5.1; users unable to upgrade have no available workarounds.

Affected products

Elastic Elasticsearch 8.0.0–8.19.18, 9.0.0–9.3.7, 9.4.0–9.4.3, 9.5.0

Timeline

2026-09-01: disclosed
2026-09-01: patched: Patches released in versions 8.19.19, 9.3.8, 9.4.4, 9.5.1

References

https://discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-9-5-1-security-update-esa-2026-143/390094

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