modelcontextprotocol python-sdk up to 1.27.1 Task Management server.experimental.enable_tasks information disclosure

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.44+

Summaryinfo

A vulnerability marked as problematic has been reported in modelcontextprotocol python-sdk up to 1.27.1. The impacted element is the function server.experimental.enable_tasks of the component Task Management. The manipulation leads to information disclosure. This vulnerability is uniquely identified as CVE-2026-52870. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in modelcontextprotocol python-sdk up to 1.27.1. This issue affects the function server.experimental.enable_tasks of the component Task Management. The manipulation with an unknown input leads to a information disclosure vulnerability. Using CWE to declare the problem leads to CWE-200. The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. Impacted is confidentiality. The summary by CVE is:

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.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-52870 since 06/08/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1592 for this issue.

Upgrading to version 1.27.2 eliminates this vulnerability.

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Productinfo

Type

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Information disclosure
CWE: CWE-200 / CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: python-sdk 1.27.2

Timelineinfo

06/08/2026 CVE reserved
07/15/2026 +37 days Advisory disclosed
07/15/2026 +0 days VulDB entry created
07/15/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-52870 (🔒)
GCVE (CVE): GCVE-0-2026-52870
GCVE (VulDB): GCVE-100-379397

Entryinfo

Created: 07/15/2026 22:32
Changes: 07/15/2026 22:32 (55)
Complete: 🔍
Cache ID: 216::103

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