CVE-2026-59279

Unbounded persistent session allocation via repeated initialize requests

Published: Aug 21, 2026Updated: Sep 16, 2026 Sources: CVE List NVDCWE-770

7.5HIGH

Description

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

No summary for this CVE yet.

CVSS Vector Breakdown

Exploitability

AV:NAttack Vector

Network

AC:LAttack Complexity

Low

PR:NPrivileges Required

None

UI:NUser Interaction

None

Scope

S:UScope

Unchanged

Impact

C:NConfidentiality

None

I:NIntegrity

None

A:HAvailability

High

Open in CVSS calculator →

Weaknesses

CWE-770

Affected Products

Spring

oss-projectaka spring framework, spring boot, spring security

Spring AI

OSS Libraries

vmware

commercial·USaka vmware inc

spring aiLibraryLibrary

AI / ML / ai-agent-tooling

Exploitability

Official Patch Available

Is your org exposed to CVE-2026-59279?Request an assessment to establish which checks are appropriate for your systems. Check my exposure

Attack Graph

Products CVE Techniques Tactics

Click technique nodes for MITRE ATT&CK details · drag to pan · Ctrl/⌘ + scroll to zoom, or go fullscreen.

MITRE ATT&CK

1 technique

Impact

View detailed technique mapping

References

https://spring.io/security/cve-2026-59279

spring.io

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-59279 and every CVE in our database. Create a free account — no credit card required.

Create Free Account

Plain-language analysis

Impact assessment and exploitation scenario in plain English

Attack graph visualization

Interactive attack path and kill chain mapping

Exploit details & PoC links

ExploitDB, Metasploit, GitHub PoCs with direct links

Nuclei scanner templates

Ready-to-use vulnerability scanner templates

Full remediation guide

Patch instructions, workarounds, and compliance impact

Interactive AI chat

Ask questions about this vulnerability in natural language

Related vulnerabilities

Semantically similar CVEs and attack patterns

REST API & MCP access

Integrate vulnerability data into your workflows