CVE-2026-41487 Details
Description
Langfuse is an open source large language model engineering platform. From version 3.68.0 to before version 3.167.0, there is a role-based-access control flaw in the LLM connection update flow. An authenticated, low-privileged user of role “member” in a project could request the update of an existing LLM connection to an attacker-controlled baseUrl, causing Langfuse to reuse the stored provider secret and redirect the test request to an attacker-controlled endpoint. This could expose the plaintext provider LLM API key for that connection. The attack is only possible if a user is already part of a project and has “member” scoped access. This issue has been patched in version 3.167.0.
A role-based access control vulnerability has been identified in Langfuse, an open-source platform for large language model engineering. This issue affects self-hosted versions from 3.68.0 prior to 3.167.0, as well as Langfuse Cloud deployments before April 9, 2026, 1PM UTC. The vulnerability allows authenticated, low-privileged users with 'member' roles to exploit the LLM connection update process. By directing an existing LLM connection to an attacker-controlled URL and omitting the provider secret, these users could intercept and access the plaintext LLM API key associated with that connection. The vulnerability is only exploitable within projects where the user has 'member' access.
Users can upgrade to Langfuse version 3.167.0 or later. For those using Langfuse Cloud, the update has already been applied. It is also recommended to rotate stored LLM provider API keys for sensitive projects with untrusted project members and to review project membership, removing untrusted users from projects with shared LLM credentials.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 8, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-284 | Improper Access Control | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| langfuse langfuse | >= 3.68.0, < 3.167.0 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 13, 2026 | Initial Analysis | [email protected] |
| May 8, 2026 | New CVE Received | [email protected] |