Skip to content
Fencer Vulns
medium 5.0

CVE-2026-40970 json

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

published 2026-04-27 6 mo ago modified 2026-10-26 13 d ago also GHSA-c96x-rpm4-349p , EUVD-2026-25908

cvss
5.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

When configured to use an SSL bundle, Spring Boot's Elasticsearch auto-configuration does not perform hostname verification when connecting to the Elasticsearch server.

Affected: Spring Boot 4.0.0–4.0.5; upgrade to 4.0.6 or later per vendor advisory.

Patch / fix

  • maven org.springframework.boot:spring-boot-elasticsearch 4.0.6
  • Spring Spring Boot 4.0.6

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-2026-40970 updated cvss 4.2

Spring Boot: Spring Boot: Missing hostname verification in Elasticsearch auto-configuration allows information disclosure

  • Red Hat AMQ Broker 7 spring-boot Red Hat AMQ Clients spring-boot Red Hat build of Apache Camel - HawtIO 4 spring-boot Red Hat build of Apache Camel for Spring Boot 4 spring-boot Red Hat build of OptaPlanner 8 spring-boot Red Hat Data Grid 8 spring-boot
    +1 more products
    Red Hat Enterprise Linux 8 log4j, log4j-jcl, log4j-web, log4j-slf4j
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux 9 log4j, log4j-jcl, log4j-slf4j
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Fuse 7 spring-boot Red Hat JBoss Enterprise Application Platform 7 spring-boot Red Hat JBoss Enterprise Application Platform 8 spring-boot Red Hat JBoss Enterprise Application Platform Expansion Pack spring-boot Red Hat OpenShift Dev Spaces devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9 Red Hat Process Automation 7 spring-boot
    +1 more products
    Red Hat Single Sign-On 7 spring-boot
    affected: workaround, no fix available “Fix deferred”

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
6 mo ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.0 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
NVD 3.1 6.8 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 5.0 CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

Affected packages

ecosystem package affected fixed in
maven org.springframework.boot:spring-boot-elasticsearch
>=4.0.0, <4.0.6
4.0.6

Affected products

  • Spring Spring Boot

Classification

Weakness
  • CWE-295 Improper Certificate Validation
Technology feeds

References

Sources

Fencer Vulns 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.