External risk intelligence

Spring Boot could allow internal attacker to intercept database data.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-40974

Spring Boot contains a flaw that could allow an internal attacker to intercept or modify data sent between the application and its database. This could expose sensitive information or lead to corrupted records, posing a significant risk to data confidentiality.

1Halo Surface Signal

Vmware Spring Boot

2.7.0 to before 2.7.333.3.0 to before 3.3.193.4.0 to before 3.4.163.5.0 to before 3.5.144.0.0 to before 4.0.6

External exposure likelihood

Halo Surface Signal score for CVE-2026-40974

The vulnerability affects backend communication between an application server and its Cassandra database. This traffic is typically confined to internal, private network segments, making it highly unlikely to be exposed to or reachable from the public internet in standard deployments.

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability in Spring Boot's Cassandra auto-configuration allows an attacker to bypass SSL hostname verification, potentially enabling them to impersonate a Cassandra server. This is critical because it could lead to sensitive data compromise or manipulation when establishing secure connections.

  • Can lead to data theft.
  • Affects applications using Cassandra.
  • Bypasses secure connection checks.

Attack Path

How an attacker could exploit the issue

An attacker could exploit this by luring a vulnerable Spring Boot application to connect to a malicious Cassandra database. Because the application fails to verify the server's hostname during the SSL handshake, it will trust the imposter. This allows the attacker to intercept sensitive data or inject malicious commands.

  • Targets applications using Spring Boot.
  • Requires network access to the application.
  • Exploits SSL connection to Cassandra.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability allows for Man-in-the-Middle attacks on SSL connections to Cassandra, which could lead to data interception and modification. While the impact is significant, attackers may find weaponizing this difficult due to the requirement of being on the same network segment as the target application and Cassandra instance.

  • Exploitation requires network proximity.
  • No public exploit available.
  • No KEV signal.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

Prioritize patching affected Spring Boot instances to versions 2.7.33, 3.3.19, 3.4.16, 3.5.14, or 4.0.6 to address the critical vulnerability in Cassandra SSL hostname verification. If immediate patching is not feasible, implement network segmentation or firewall rules to restrict access to the Cassandra database, ensuring only trusted application instances can connect. Monitor network traffic for any unusual connections or authentication attempts to the Cassandra cluster.

  • Patch Spring Boot to fixed versions.
  • Isolate Cassandra connections.
  • Monitor for suspicious traffic.

Frequently asked questions

What is Spring Boot's Cassandra auto-configuration?

Spring Boot is a popular framework used to create standalone, production-grade Spring-based applications. Its Cassandra auto-configuration is a feature that simplifies the process of connecting Spring applications to a Cassandra NoSQL database, especially when using SSL for secure communication.

What kind of weakness does CVE-2026-40974 describe?

CVE-2026-40974 describes a hostname verification failure, which falls under the CWE-295 weakness class. This means that when an application using Spring Boot attempts to establish a secure SSL connection to Cassandra, it doesn't properly check if the server's identity matches the expected hostname, allowing for potential impersonation.

What are the conditions for this CVE to be triggered?

This vulnerability is triggered when a Spring Boot application attempts to establish an SSL connection to a Cassandra database without proper hostname verification. An attacker would need to be in a position to intercept or redirect this connection to a malicious server. Connections that do not use SSL or use other database clients are not affected by this specific vulnerability.

Who should be concerned about this external vulnerability?

Organizations using Spring Boot with Cassandra and SSL for backend communication should be concerned. Halo Surface Signal indicates this is an external threat, meaning it has the potential to be reachable from the internet, although its exploitation typically requires being within the network path to the Cassandra database.

What is the first step to address this Spring Boot vulnerability?

The primary immediate action is to update your Spring Boot instances to a patched version. Specifically, versions 2.7.33, 3.3.19, 3.4.16, 3.5.14, or 4.0.6 contain the fix for this issue. This resolves the underlying problem of improper SSL hostname verification.

References