CVE-2026-108714 MCP Kotlin SDK through 0.15.0 Memory Exhaustion via Application.mcpWebSocket
Remote attackers can exhaust server memory by sending large WebSocket frame headers, causing denial of service in the MCP Kotlin SDK.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-108714?
CVE-2026-108714 is a high-severity denial of service vulnerability in modelcontextprotocol kotlin-sdk, published on 11 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-770
Which versions are affected by CVE-2026-108714?
How do I fix CVE-2026-108714?
No fix has been published for CVE-2026-108714 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-108714 being exploited?
There is no known exploitation of CVE-2026-108714 in the wild and no public exploit code.
Sources
Also known as GHSA-645v-p22p-m3jx.