MediumVulnerability

CVE-2026-12763: IBM Langflow OSS cross-user MCP server context access via cache key isolation

Source: NVD(opens in a new tab)
Identifier: CVE-2026-12763
Published: September 14, 2026
Record updated: October 9, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.2%

Summary

IBM Langflow OSS versions 1.0.0 through 1.11.5 contain a flaw in the MCP Tools component. An authenticated attacker can reach another user's MCP server context because cache keys are not properly isolated.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Details

Scores and exploitation

CVSS score: 4.2(medium)
CVSS vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector: network
Attack complexity: high
Privileges required: low
User interaction: none
EPSS: 0.2%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 4, 2026.
Disclosure date: September 14, 2026

Weaknesses and techniques

Weakness (CWE): CWE-306
Attack pattern (CAPEC): CAPEC-115

Classification

Attack type: Other
Attack sophistication: Moderate
AI component targeted: Framework
Impact: Confidentiality
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-12763

First tracked: September 14, 2026 at 08:07 PM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 90% (self-assessed)

Topics

Model Context Protocol

Summary

Mitigation

Topics

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