Bug 2549285 (CVE-2026-108859)

Summary: CVE-2026-108859 github.com/mark3labs/mcp-go: mcp-go: Denial of Service via unbounded HTTP request body buffering
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: mwringe
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in mcp-go. The HTTP server implementation does not restrict the size of incoming HTTP POST request bodies before buffering them into memory. A remote, unauthenticated attacker can exploit this vulnerability by sending excessively large or multiple concurrent requests, causing memory exhaustion and leading to a Denial of Service (DoS) when the server crashes.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-11 13:41:29 UTC
mcp-go through 1.2.1 contains a denial of service vulnerability in StreamableHTTPServer.ServeHTTP that allows remote unauthenticated attackers to exhaust memory by sending oversized POST bodies. Attackers can send arbitrarily large or many concurrent POST requests, read fully via io.ReadAll before validation, to degrade or OOM-kill the server process.