GHSA-c96x-rpm4-349p: org.springframework.boot:spring-boot-elasticsearch (CVE-2026-40970)

Spring Boot's Elasticsearch auto-configuration doesn't perform hostname verification when connecting to the Elasticsearch server.

CVSS 5.0 MediumEPSS 0.0014 · 3rd percentile

Published by the GitHub Advisory Database at 27 Apr 2026, 21:31 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
org.springframework.boot:spring-boot-elasticsearch	Maven	>=4.0.0, <4.0.6	4.0.6

Identifiers

GHSA-c96x-rpm4-349p · CVE-2026-40970

Weakness (CWE)

CWE-295

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Spring Boot's spring-boot-elasticsearch module, versions 4.0.0 through 4.0.5, does not perform hostname verification when connecting to Elasticsearch with an SSL bundle configured. An attacker able to intercept or redirect the network connection could present a certificate for another host and the connection would not be rejected for that reason. Upgrade spring-boot-elasticsearch to 4.0.6 or later.

Written 3 Nov 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.0	Medium	3.1	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L	CNA (vmware)

CISA KEV Not listed.
EPSS 0.0014, the 3rd percentile, on 10 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:20 UTC First seen by agentprime
31 Oct 2026, 14:20 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.