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Langfuse: Improper role-based-access control in Langfuse LLM connection management allowed users of role “member” to retrieve stored LLM provider API keys

Type: advisorySources: OSV

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.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-41487
Confirmed fixed CVEs
Not specified
Updated in this feed
5 Nov 2026, 03:30 UTC · Revision 1

Source evidence

Langfuse: Improper role-based-access control in Langfuse LLM connection management allowed users of role “member” to retrieve stored LLM provider API keys

core-osv · Original source

Published 8 May 2026, 14:27 UTC

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.

osv:CVE-2026-41487
Complete source record
{
  "id": "222b7139fe40434813c6879e89ad5806117f2eb6fb30c1777855d4bad366ecd8",
  "url": "https://osv.dev/vulnerability/CVE-2026-41487",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Langfuse: Improper role-based-access control in Langfuse LLM connection management allowed users of role “member” to retrieve stored LLM provider API keys",
    "summary": "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.",
    "evidence": "osv:CVE-2026-41487",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-41487",
      "aliases": [
        "CVE-2026-41487",
        "GHSA-2524-j966-gfgh"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/langfuse/langfuse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "aae1909466a4f676d77621a6349905d16b73873e"
                },
                {
                  "fixed": "dd632fea9efe6cc9e125f3dcec051d4f3bab7669"
                },
                {
                  "fixed": "7527bb0d84bc0a3dc24a4b16d22ed2e46e6dddff"
                },
                {
                  "fixed": "e12386f9d4368bbfff24a4ad7fd53641091605ff"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:langfuse:langfuse:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.68.0"
                      },
                      {
                        "fixed": "3.167.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7527bb0d84bc0a3dc24a4b16d22ed2e46e6dddff"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "e12386f9d4368bbfff24a4ad7fd53641091605ff"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "dd632fea9efe6cc9e125f3dcec051d4f3bab7669"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.167.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.164.0",
            "v3.163.0",
            "v3.162.0",
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            "v3.100.0",
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-41487.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:42.268399493Z",
      "provider": "osv",
      "references": [
        "https://github.com/langfuse/langfuse/releases/tag/v3.167.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41487.json",
        "https://github.com/langfuse/langfuse/security/advisories/GHSA-2524-j966-gfgh",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-41487",
        "https://github.com/langfuse/langfuse/commit/7527bb0d84bc0a3dc24a4b16d22ed2e46e6dddff",
        "https://github.com/langfuse/langfuse/commit/e12386f9d4368bbfff24a4ad7fd53641091605ff",
        "https://github.com/langfuse/langfuse/pull/13027",
        "https://github.com/langfuse/langfuse/pull/13055"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-284"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41487.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-41487",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 509866,
  "published_at": "2026-05-08T14:27:48.588+00:00"
}