CVE-2026-12763
Langflow is vulnerable to authentication bypass and insufficient session expiration
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Langflow is vulnerable to authentication bypass and insufficient session expiration
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.
- Record
CVE-2026-12763- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
EUVDEUVD-2026-78087
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.
- Record
EUVD-2026-78087- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-vhrg-69rg-gwv4
IBM Langflow OSS 1.0.0 through 1.11.5 could allow an authenticated attacker to access another...
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.
- Record
GHSA-vhrg-69rg-gwv4- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-306
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-12763- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-306
- Updated
- 2026-11-03
OSV
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.
- Record
CVE-2026-12763- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Updated
- 2026-11-05
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| references | OSV | |
| facts, products, references | NVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-12763 is a medium vulnerability (CVSS 4.2) in Ibm Langflow Oss, published September 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.19%, the 8th percentile. No source names a fixed version.