CVE-2026-59279

Unbounded persistent session allocation via repeated initialize requests

Published Aug 21, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
References
History
Type Values Removed Values Added
First Time appeared Vmware
Vmware spring Ai
CPEs cpe:2.3:a:vmware:spring_ai:*:-:*:*:*:*:*:*
Vendors & Products Vmware
Vmware spring Ai
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Spring
Spring spring Ai
Vendors & Products Spring
Spring spring Ai
Type Values Removed Values Added
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
Title Unbounded persistent session allocation via repeated initialize requests
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
vmware
Published
Updated
Aug 21, 2026, 2:28 PM
Reserved
Jul 4, 2026, 6:13 PM
Status
Analyzed
Published
Aug 21, 2026, 12:16 PM
Modified
Oct 16, 2026, 3:10 PM