CVE-2026-41487Network attack vector

Provider API key disclosure via redirected connection test

Published May 8, 2026 · Updated May 8, 2026

Improper access control in Langfuse 3.68.0 through versions before 3.167.0 allows remote authenticated users to disclose provider API keys. The llmApiKey.testUpdate flow accepts a member-supplied baseURL, decrypts and reuses the existing connection secret, then sends a test request to that destination. Project membership with the member role and an existing LLM connection are required; the attacker-controlled endpoint receives the plaintext credential.

CVSS severity5.3
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Langfuse 3.68.0 through versions before 3.167.0 allows remote authenticated users to disclose provider API keys. The llmApiKey.testUpdate flow accepts a member-supplied baseURL, decrypts and reuses the existing connection secret, then sends a test request to that destination. Project membership with the member role and an existing LLM connection are required; the attacker-controlled endpoint receives the plaintext credential.

The record

CVE
CVE-2026-41487
Published
May 8, 2026
Updated
May 8, 2026
Vendor
Langfuse
Product
Langfuse
Classifications
CWE-284, T1212
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 3.68.0, < 3.167.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Langfuse · Langfuseversion=>= 3.68.0, < 3.167.0

Published CVSS scores

5.3GitHub, Inc.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
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1212Exploitation for Credential Access

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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