Auth bypass in Langfuse

CVE-2026-24055

Langfuse is an open source large language model engineering platform. In versions 3.146.0 and below, the /api/public/slack/install endpoint initiates Slack OAuth using a projectId provided by the client without authentication or authorizat…

EPSS: 0.004 (32.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

  • Langfuse — versions >= 3.89.0, < 3.147.0

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-24055?
CVE-2026-24055 is a medium-severity vulnerability in Langfuse, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-01-22.
How severe is CVE-2026-24055?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2026-24055 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.