CVE-2026-14539Denial of Service via Unrestricted Payload Buffering in MCP Toolbox
Updated under an hour ago ()
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It affects Google mcp-toolbox and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Free account, 1 product
An allocation of resources without limits vulnerability in the HTTP handler component of Google mcp-toolbox versions up to and including 1.4.0 allows an unauthenticated attacker to cause a denial of service (DoS). The /mcp endpoint handler reads incoming payloads directly into system memory using an unrestricted buffer loop (io.ReadAll) without applying defensive constraints such as http.MaxBytesReader or pre-read Content-Length enforcement. By submitting a single, massive HTTP request body, an attacker can linearly consume available host memory until the runtime process is terminated by an Out-Of-Memory (OOM) error.
- CVSS
- 6.6 MEDIUM (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
- Weakness (CWE)
- CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- NVD analysis
- Analyzed
- Record last updated
- Jul 31, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Google mcp-toolbox google:mcp_toolbox (from the name) | from 0.0.0 through 1.4.0 | CNA record |
google mcp_toolbox_for_databases google:mcp_toolbox_for_databases | before 1.5.0 | NVD |
References
- https://github.com/googleapis/mcp-toolbox/pull/3216issue-tracking, patch
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.