{"vulnerability": "cve-2026-6311", "sightings": [{"uuid": "ddde1387-65ab-44ee-ae68-3ee30c42e2cf", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-6311", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/3mjksflkcpd2o", "content": "", "creation_timestamp": "2026-04-15T21:06:32.747300Z"}, {"uuid": "a585b7f1-1aa8-487e-bc42-a6e83ab92af7", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-6311", "type": "seen", "source": "https://www.hkcert.org/security-bulletin/google-chrome-multiple-vulnerabilities_20260416", "content": "", "creation_timestamp": "2026-04-15T18:00:00.000000Z"}, {"uuid": "ca951100-5663-4cb3-91e9-42facac78e60", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-6311", "type": "seen", "source": "https://www.hkcert.org/security-bulletin/microsoft-edge-multiple-vulnerabilities_20260420", "content": "", "creation_timestamp": "2026-04-19T20:00:00.000000Z"}, {"uuid": "6121d446-1cb0-4002-81be-1666a06be258", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-6311", "type": "published-proof-of-concept", "source": "Telegram/0zmBng2ph0j5-h51LqidOz9H-G3O8PUZqZfxER_d38YEET8", "content": "", "creation_timestamp": "2026-04-15T23:26:54.000000Z"}, {"uuid": "be1fe1ce-aa39-4864-8dee-6874ab024338", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-63119", "type": "published-proof-of-concept", "source": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-7683-3w9x-ch42", "content": "", "creation_timestamp": "2026-07-30T16:35:27.916843Z"}, {"uuid": "b5fb0395-3e14-44c3-a464-84b0b9e78485", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "86ecb4e1-bb32-44d5-9f39-8a4673af8385", "vulnerability": "CVE-2026-63118", "type": "published-proof-of-concept", "source": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "content": "", "creation_timestamp": "2026-07-30T16:35:30.654080Z"}, {"uuid": "8ab86efd-a69c-46c7-a647-64d810bfba9a", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-63119", "type": "seen", "source": "https://gist.github.com/alon710/14986c8aa9f0de6cc9812b6e85b52624", "content": "# CVE-2026-63119: CVE-2026-63119: Denial of Service via Uncontrolled Resource Consumption in Model Context Protocol Ruby SDK\n\n> **CVSS Score:** 6.2\n> **Published:** 2026-07-30\n> **Full Report:** https://cvereports.com/reports/CVE-2026-63119\n\n## Summary\nCVE-2026-63119 is a high-impact denial-of-service vulnerability in the Model Context Protocol (MCP) Ruby SDK (distributed as the 'mcp' gem) before version 0.23.0. The vulnerability allows an attacker to cause resource exhaustion and process termination by streaming unbounded input to standard I/O streams.\n\n## TL;DR\nUnbounded standard input stream reading in the Model Context Protocol Ruby SDK allows connected peers or subprocesses to deplete system memory and crash the host application via a continuous stream of data lacking newline separators.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-400 / CWE-770\n- **Attack Vector**: Local (AV:L)\n- **CVSS v3.1 Score**: 6.2\n- **EPSS Score**: 0.00129\n- **Impact Type**: Availability (High)\n- **Exploit Status**: Proof of Concept Available\n- **KEV Status**: Not Listed\n\n## Affected Systems\n\n- Model Context Protocol (MCP) Ruby SDK prior to version 0.23.0\n- **modelcontextprotocol/ruby-sdk**: < 0.23.0 (Fixed in: `0.23.0`)\n\n## Mitigation\n\n- Upgrade the 'mcp' Ruby gem to version 0.23.0 or higher\n- Enforce explicit byte-limit configurations on all standard input/output stream readers\n- Discard and re-initialize transport objects immediately if a stream handler error is raised\n\n**Remediation Steps:**\n1. Open the project's Gemfile\n2. Update the 'mcp' gem definition to require version '>= 0.23.0'\n3. Run 'bundle update mcp' to install the patched library version\n4. Restart any running client or server instances utilizing the SDK\n\n## References\n\n- [NVD - CVE-2026-63119 Detail](https://nvd.nist.gov/vuln/detail/CVE-2026-63119)\n- [CVE.org CVE-2026-63119 Record](https://www.cve.org/CVERecord?id=CVE-2026-63119)\n- [GitHub Security Advisory GHSA-7683-3w9x-ch42](https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-7683-3w9x-ch42)\n- [MCP Ruby SDK Release v0.23.0 Notes](https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/CVE-2026-63119) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-07-31T05:31:42.169060Z"}, {"uuid": "4f83b35a-643c-4d9f-bc95-3837c0f38dc4", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-63118", "type": "seen", "source": "https://gist.github.com/alon710/f097a8ec4fd3160f0611d4f0d84400e7", "content": "# CVE-2026-63118: CVE-2026-63118: DNS-Rebinding and Cross-Origin Request Execution in Model Context Protocol (MCP) Ruby SDK\n\n> **CVSS Score:** 6.9\n> **Published:** 2026-07-30\n> **Full Report:** https://cvereports.com/reports/CVE-2026-63118\n\n## Summary\nA critical vulnerability (CVE-2026-63118) in the Model Context Protocol (MCP) Ruby SDK allows attackers to execute arbitrary JSON-RPC commands and exfiltrate sensitive local data from an MCP server bound to the local loopback interface. This is achieved through DNS-rebinding and cross-origin request execution due to missing validation of the HTTP Host and Origin headers in the StreamableHTTPTransport component.\n\n## TL;DR\nA DNS-rebinding flaw in the MCP Ruby SDK (< 0.23.0) allows malicious sites to bypass the browser Same-Origin Policy and run arbitrary local tools.\n\n## Exploit Status: POC\n\n## Technical Details\n\n- **CWE ID**: CWE-346, CWE-350\n- **Attack Vector**: Network (AV:N)\n- **CVSS Score**: 6.9 (Medium)\n- **Exploit Status**: PoC Available\n- **Affected Component**: StreamableHTTPTransport\n- **Fixed Version**: v0.23.0\n- **CISA KEV Status**: Not Listed\n\n## Affected Systems\n\n- Model Context Protocol (MCP) Ruby SDK (mcp gem)\n- **mcp**: < 0.23.0 (Fixed in: `v0.23.0`)\n\n## Mitigation\n\n- Upgrade the mcp gem to version 0.23.0 or higher.\n- Configure upstream Host and Origin validation in reverse proxies.\n- Restrict server binds strictly to the loopback interface (127.0.0.1 or ::1).\n\n**Remediation Steps:**\n1. Modify the Gemfile to require 'mcp' version 0.23.0 or higher.\n2. Run 'bundle update mcp' to apply the update.\n3. Optionally define 'allowed_hosts' and 'allowed_origins' parameters if binding to non-loopback interfaces.\n\n## References\n\n- [GHSA-rjr6-rcgv-9m7m: DNS-rebinding and cross-origin request execution in MCP Ruby SDK](https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m)\n- [CVE-2026-63118 Record](https://www.cve.org/CVERecord?id=CVE-2026-63118)\n- [NVD - CVE-2026-63118 Detail](https://nvd.nist.gov/vuln/detail/CVE-2026-63118)\n\n\n---\n*Generated by [CVEReports](https://cvereports.com/reports/CVE-2026-63118) - Automated Vulnerability Intelligence*", "creation_timestamp": "2026-07-31T07:31:42.012680Z"}, {"uuid": "4eb49b65-3712-4a53-8c08-c93efcad90a5", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-6311", "type": "seen", "source": "https://bsky.app/profile/cyberhub.blog/post/3mno3gxaqvx25", "content": "\ud83d\udccc CVE-2026-6311 - Uninitialized Use in Accessibility in Google Chrome on Windows prior to 147.0.7727.101 allowed a remote attacker who had compromised the renderer proc... https://www.cyberhub.blog/cves/CVE-2026-6311", "creation_timestamp": "2026-06-07T02:07:08.310278Z"}, {"uuid": "5d394ead-5b5a-4f38-b887-2546653c03c0", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-63118", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/3mrssjm3jv424", "content": "CVE-2026-63118 - MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection\nCVE ID : CVE-2026-63118\n \n Published : July 29, 2026, 8:17 p.m. | 26\u00a0minutes ago\n \n Description : MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and ...", "creation_timestamp": "2026-07-29T20:51:38.481124Z"}, {"uuid": "4e9bda9b-ae9b-40db-b12e-13a7e1c0d692", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-63119", "type": "seen", "source": "https://bsky.app/profile/cve.skyfleet.blue/post/3mrsuhri6me23", "content": "CVE-2026-63119 - MCP Ruby SDK: Unbounded line buffer in stdio transports leads to memory exhaustion (DoS)\nCVE ID : CVE-2026-63119\n \n Published : July 29, 2026, 8:17 p.m. | 26\u00a0minutes ago\n \n Description : MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers ...", "creation_timestamp": "2026-07-29T21:26:24.391949Z"}]}