CVE-2026-41487

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.

Weakness classification

• security-advisories@github.com: CWE-284

Primary references

• security-advisories@github.com — Patch
• security-advisories@github.com — Patch
• security-advisories@github.com — Issue Tracking, Patch
• security-advisories@github.com — Issue Tracking, Patch
• security-advisories@github.com — Release Notes
• security-advisories@github.com — Mitigation, Patch, Vendor Advisory