{"answers":{"affected":"3 open source packages ship an affected version, including mcp. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-52870 in the wild and no public exploit code.","fix":"Upgrade mcp to 1.27.2 or later.","what":"CVE-2026-52870 is a high-severity missing authorization vulnerability in modelcontextprotocol python-sdk, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-52870 and fix it if it is affected.\n\nWhat it is: CVE-2026-52870 is a high-severity missing authorization vulnerability in modelcontextprotocol python-sdk, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-52870 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mcp (PyPI): affected from 1.23.0; fixed in 1.27.2\n- mcp (PyPI): affected from 1.23.0; fixed in 1.27.2\n- mcp (PyPI): affected from 1.23.0; fixed in 1.27.2\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-52870/ (Markdown: https://insights.sbomify.com/CVE-2026-52870/index.md)","id":"CVE-2026-52870","markdown":"https://insights.sbomify.com/CVE-2026-52870/index.md","name":"CVE-2026-52870","record":{"aliases":["ECHO-686f-4b2a-3dd3","GHSA-hvrp-rf83-w775","MINI-2p5p-6fph-q54f","MINI-2vqf-fvc7-2m6g","MINI-66cj-vvx7-mrpc","MINI-7p24-89h3-vqc8","MINI-8fq3-wj4q-2qmc","MINI-c536-gg75-h86h","MINI-crj4-792v-p42j","MINI-f2vx-226h-5c7m","MINI-g965-6pcj-8442","MINI-hcqr-5752-v68j","MINI-hhvq-g349-36pj","MINI-hmh8-jxjr-994x","MINI-jh4q-f668-fp74","MINI-qc9p-5xc4-rhxp","MINI-w48m-fmjg-j2gx","MINI-wmf3-j9hv-59wf","PYSEC-2026-3481","ROOT-APP-PYPI-CVE-2026-52870"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_read","denial_of_service"],"network_reachable":"yes","non_default_config":true,"product_category":"MCP Python SDK","requires_auth":"low_privilege","summary":"Attackers can access and cancel other clients' tasks in MCP Python SDK when experimental task handlers are enabled.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mcp_python_sdk","vendor":"lfprojects"}],"cvss":{"score":7.6,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L","version":"3.1"},"cwes":[{"id":"CWE-862","name":"Missing Authorization"}],"description":"The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). From 1.23.0 until 1.27.2, default handlers installed by server.experimental.enable_tasks() for tasks/list, tasks/get, tasks/result, and tasks/cancel operate only on task identifiers without recording the session that created each task, allowing any connected client to enumerate, read results from, consume messages for, or cancel other clients' tasks. This issue is fixed in version 1.27.2.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"MCP Python SDK: Experimental task handlers allow any client to access and cancel other clients' tasks","id":"CVE-2026-52870","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"missing_authorization","year":"2026"},"n_packages":3,"n_references":4,"next":{"headline":"Streambert: Local File Exfiltration and Overwrite via Subtitle file: Protocol","id":"CVE-2026-52872"},"packages":[{"ecosystem":"PyPI","fixed":["1.27.2"],"introduced":["1.23.0"],"last_affected":[],"package":"mcp","purl":null,"source":"GHSA-hvrp-rf83-w775"},{"ecosystem":"PyPI","fixed":["1.27.2"],"introduced":["1.23.0"],"last_affected":[],"package":"mcp","purl":"pkg:pypi/mcp","source":"GHSA-hvrp-rf83-w775"},{"ecosystem":"PyPI","fixed":["1.27.2"],"introduced":["1.23.0"],"last_affected":[],"package":"mcp","purl":"pkg:pypi/mcp","source":"PYSEC-2026-3481"}],"prev":{"headline":"MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal","id":"CVE-2026-52869"},"products":["python-sdk"],"published":"2026-07-15","related":[{"cvss_score":7.6,"headline":"MCP Python SDK: WebSocket server transport does not support Host/Origin validation","id":"CVE-2026-59950","kev_date_added":null,"published":"2026-07-15"},{"cvss_score":7.6,"headline":"DNS Rebinding Protection Disabled by Default in Model Context Protocol Python SDK for Servers Running on Localhost","id":"CVE-2025-66416","kev_date_added":null,"published":"2025-12-02"},{"cvss_score":7.1,"headline":"MCP Python SDK: HTTP transports serve session requests without verifying the authenticated principal","id":"CVE-2026-52869","kev_date_added":null,"published":"2026-07-15"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-16","vendors":["modelcontextprotocol"]},"summary":"Attackers can access and cancel other clients' tasks in MCP Python SDK when experimental task handlers are enabled.","url":"https://insights.sbomify.com/CVE-2026-52870/"}