CVE-2026-59279 — Unbounded persistent session allocation via repeated initialize requests
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 …
Published: 2026-08-21 · CVSS: 7.5 · CVSS 3.1
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
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7