Resource exhaustion in Spring Ai

CVE-2026-59279

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (44.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 44.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-59279: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-59279?
CVE-2026-59279 is a high-severity vulnerability in Spring Ai, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-08-21.
How severe is CVE-2026-59279?
High severity. CVSS v3 base score is 7.5 out of 10.