Langfuse up to 2.95.10/3.124.0 API information exposure

Summaryinfo

A vulnerability, which was classified as problematic, was found in Langfuse up to 2.95.10/3.124.0. Affected by this issue is some unknown functionality of the component API. Executing a manipulation can lead to information exposure. This vulnerability is handled as CVE-2025-64504. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Langfuse up to 2.95.10/3.124.0 and classified as problematic. This vulnerability affects some unknown functionality of the component API. The manipulation with an unknown input leads to a information exposure vulnerability. The CWE definition for the vulnerability is CWE-202. When trying to keep information confidential, an attacker can often infer some of the information by using statistics. As an impact it is known to affect confidentiality. CVE summarizes:

Langfuse is an open source large language model engineering platform. Starting in version 2.70.0 and prior to versions 2.95.11 and 3.124.1, in certain project membership APIs, the server trusted a user‑controlled orgId and used it in authorization checks. As a result, any authenticated user on the same Langfuse instance could enumerate names and email addresses of users in another organization if they knew the target organization’s ID. Disclosure is limited to names and email addresses of members/invitees. No customer data such as traces, prompts, or evaluations is exposed or accessible. For Langfuse Cloud, the maintainers ran a thorough investigation of access logs of the last 30 days and could not find any evidence that this vulnerability was exploited. For most self-hosting deployments, the attack surface is significantly reduced given an SSO provider is configured and email/password sign-up is disabled. In these cases, only users who authenticate via the Enterprise SSO IdP (e.g. Okta) would be able to exploit this vulnerability to access the member list, i.e. internal users getting access to a list of other internal users. In order to exploit the vulnerability, the actor must have a valid Langfuse user account within the same instance, know the target orgId, and use the request made to the API that powers the frontend membership tables, including their project/user authentication token, while changing the orgId to the target organization. Langfuse Cloud (EU, US, HIPAA) were affected until fix deployment on November 1, 2025. The maintainers reviewed the Langfuse Cloud access logs from the past 30 days and found no evidence that this vulnerability was exploited. Self-Hosted versions which contain patches include v2.95.11 for major version 2 and v3.124.1 for major version 3. There are no known workarounds. Upgrading is required to fully mitigate this issue.

The advisory is shared for download at github.com. This vulnerability was named CVE-2025-64504 since 11/05/2025. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1592.

Upgrading to version 2.95.11 or 3.124.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 67990ebfdcf0f0c32a6710efa7ddbda073812ab4 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• Langfuse

Version

• 2.95.0
• 2.95.1
• 2.95.2
• 2.95.3
• 2.95.4
• 2.95.5
• 2.95.6
• 2.95.7
• 2.95.8
• 2.95.9
• 2.95.10
• 3.124

License

• open-source

Website

• Product: https://github.com/langfuse/langfuse/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion