CVE-2026-40970: When configured to use an SSL bundle, Spring Boot's Elasticsearch auto-configuration does not perform hostname

Routine

MEDIUM 5.0UPGRADE

CVE-2026-40970 is a medium-severity flaw (CVSS 5.0) affecting spring boot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
Attack vector	Adjacent network
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.1% (top 97%)
CISA exploited list	No
Weakness	CWE-295
Published	2026-04-27
Last modified	2026-10-26

Publisher (CNA): VMware · Vendor: vmware

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-27 19:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

vmware spring boot UPGRADE

Affected: >= 4.0.0 and < 4.0.6

Fixed in: 4.0.6

Safe to downgrade to: a release before 4.0.0

1. Check installed version

apt-cache policy spring-boot || rpm -q spring-boot || spring-boot --version

2. UPGRADE to 4.0.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade spring-boot

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade spring-boot

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 4.0.0 (Debian / Ubuntu)

apt-cache madison spring-boot sudo apt install spring-boot=<VERSION_BEFORE_4.0.0> sudo apt-mark hold spring-boot

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list spring-boot sudo dnf downgrade spring-boot-<VERSION_BEFORE_4.0.0> sudo dnf versionlock add spring-boot

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-40970?

spring boot: upgrade to 4.0.6. Exact commands for each OS are on this page.

Is CVE-2026-40970 being exploited?

CVE-2026-40970 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-40970 affect?

CVE-2026-40970 affects spring boot. Severity is medium (CVSS 5.0). 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 vendo

How urgent is CVE-2026-40970?

Priority 18/100. No elevated risk signals yet.

Software pages

Spring Framework vulnerabilities · Elasticsearch vulnerabilities · VMware vulnerabilities

References

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