How severe is CVE-2026-52870?

CVE-2026-52870 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.

Is CVE-2026-52870 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-52870?

CVE-2026-52870 affects Lfprojects Mcp Python Sdk. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-52870?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-52870 published?

CVE-2026-52870 was published on 2026-07-15 and last updated on 2026-07-17.

CVE-2026-52870

CVE-2026-52870 is a high-severity vulnerability in Lfprojects Mcp Python Sdk with a CVSS 3.x base score of 7.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-862.

Key facts

Severity: High (CVSS 3.x base score 7.6)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-862
Affected product: Lfprojects Mcp Python Sdk
Published: 2026-07-15
Last modified: 2026-07-17

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.

Frequently asked questions

What is CVE-2026-52870?: 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.
How severe is CVE-2026-52870?: CVE-2026-52870 has a CVSS 3.x base score of 7.6, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability low.
Is CVE-2026-52870 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-52870?: CVE-2026-52870 affects Lfprojects Mcp Python Sdk. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-52870?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-52870 published?: CVE-2026-52870 was published on 2026-07-15 and last updated on 2026-07-17.

References

Affected products (1)

cpe:2.3:a:lfprojects:mcp_python_sdk:*:*:*:*:*:*:*:*

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