CVE-2026-59279
Published:August 21, 2026
Updated:September 24, 2026
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 Packages
https://github.com/spring-projects/spring-ai.git (GITHUB):
Affected version(s) =v2.0.0 <v2.0.1Fix Suggestion:
Update to version v2.0.1org.springframework.ai:mcp-spring-webflux (JAVA):
Affected version(s) =2.0.0 <2.0.1Fix Suggestion:
Update to version 2.0.1org.springframework.ai:mcp-spring-webmvc (JAVA):
Affected version(s) =2.0.0 <2.0.1Fix Suggestion:
Update to version 2.0.1Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.39