---
id: CVE-2026-59279
title: >-
  The MCP Streamable HTTP server transport (WebFlux and WebMvc variants) does
  not place any limit on the number of sessions it retains, and by default does
  not require clients to be authenticated
summary: >-
  The MCP Streamable HTTP server transport (WebFlux and WebMvc variants) does
  not place any limit on the number of sessions it retains, and by default does
  not require clients to be authenticated. As a result, a remote attacker can
  cause t…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: vmware
product: spring_ai
affected:
  - 'spring_ai >= 2.0.0, < 2.0.1'
patched:
  - spring_ai 2.0.1
published: '2026-08-21'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T14:06:48.447'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-59279'
references:
  - url: 'https://spring.io/security/cve-2026-59279'
    label: security@vmware.com
tags:
  - nvd
epss: 0.00549
epssPercentile: 0.43564
ingestedAt: '2026-09-16T14:57:28.003Z'
---

## Overview

The MCP Streamable HTTP server transport (WebFlux and WebMvc variants) does not place any limit on the number of sessions it retains, and by default does not require clients to be authenticated. As a result, a remote attacker can cause the server to accumulate an unbounded number of sessions over time, gradually exhausting available memory and ultimately causing a Denial of Service that affects all legitimate clients.
Affected versions:
Spring AI: 2.0.0

## Affected

- `spring_ai >= 2.0.0, < 2.0.1`

## Remediation

Upgrade past the affected range:

- `spring_ai 2.0.1`