High 7.5Published Oct 11, 2026

CVE-2026-108714MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocket

Updated under an hour ago (Oct 28, 2026, 8:23 AM ET)

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It affects modelcontextprotocol kotlin-sdk. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.36%, higher than 28% of scored CVEs.

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Every CVE for modelcontextprotocol kotlin-sdk

Exploited in the last 30 days

MCP Kotlin SDK through 0.15.0 contains an uncontrolled memory allocation vulnerability that allows remote clients to exhaust server memory because Application.mcpWebSocket installs Ktor WebSockets without a maxFrameSize limit. Attackers can send small frame headers declaring payloads near 2 GiB over one or a few connections, forcing huge heap allocations and causing denial of service.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-770
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.36% (percentile 28)
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 11, 2026

Affected products

Affected products

modelcontextprotocol kotlin-sdk modelcontextprotocol:kotlin_sdk (from the name)	through 0.15.0	CNA record

References

References

https://hackmd.io/@haind/mcp-kotlin-sdk-websocket-frame-allocation-dos	third-party-advisory
https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-server/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/server/WebSocketMcpKtorServerExtensions.kt#L41-L63	technical-description
https://github.com/modelcontextprotocol/kotlin-sdk/blob/0.15.0/kotlin-sdk-core/src/commonMain/kotlin/io/modelcontextprotocol/kotlin/sdk/shared/WebSocketMcpTransport.kt#L60-L85	technical-description
https://github.com/modelcontextprotocol/kotlin-sdk	product
https://www.vulncheck.com/advisories/mcp-kotlin-sdk-through-0.15.0-memory-exhaustion-via-application-mcpwebsocket	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.