What is CVE-2026-6542?

CVE-2026-6542 is a medium-severity vulnerability in IBM Langflow Oss, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-04-30.

How severe is CVE-2026-6542?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in IBM Langflow Oss

CVE-2026-6542

IBM Langflow OSS 1.0.0 through 1.8.4 could allow any user to supply a flow_id to read transaction logs and vertex build data belonging to other users, and to delete persisted vertex build data for another user's flow.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published 2026-04-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (26.5th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002

Affected products

IBM Langflow Oss — versions 1.0.0
Langflow

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

www.ibm.com/support/pages/node/7270886 (vendor-advisory, Third Party Advisory, patch)

Frequently asked questions

What is CVE-2026-6542?: CVE-2026-6542 is a medium-severity vulnerability in IBM Langflow Oss, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 6.5/10. Published 2026-04-30.
How severe is CVE-2026-6542?: Medium severity. CVSS v3 base score is 6.5 out of 10.