What is CVE-2026-12763?

CVE-2026-12763 is a medium-severity vulnerability in IBM Langflow Oss, classified under Missing Authentication for Critical Function. CVSS score: 4.2/10. Published 2026-09-14.

How severe is CVE-2026-12763?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Auth bypass in IBM Langflow Oss

CVE-2026-12763

IBM Langflow OSS 1.0.0 through 1.11.5 could allow an authenticated attacker to access another user's MCP server context due to improper cache key isolation in the MCP Tools component.

Vulnerability class: Broken Authentication

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N.

Affected products

Ibm Langflow Oss

Weakness classification (CWE)

CWE-306 — Missing Authentication for Critical Function

References

psirt@us.ibm.com (vendor-advisory, patch)

Frequently asked questions

What is CVE-2026-12763?: CVE-2026-12763 is a medium-severity vulnerability in IBM Langflow Oss, classified under Missing Authentication for Critical Function. CVSS score: 4.2/10. Published 2026-09-14.
How severe is CVE-2026-12763?: Medium severity. CVSS v3 base score is 4.2 out of 10.