CVE Intelligence
Medium

CVE-2025-64504 — Langfuse vulnerable to cross‑organization enumeration of member & invitation lists via project membership APIs

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.

Published Nov 10, 2025 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.3% (30-day exploitation probability)+4
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.34%
ahead of 26% of scored CVEs · Oct 14, 2026
Affects
Langfuse
Langfuse
CVSS base
5.0
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Langfuse Langfuse).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Langfuse Langfuse ≥ 2.70.0 and < 2.95.11≥ 3.0.0 and < 3.124.1 Vulnerable NIST National Vulnerability Database
Langfuse Langfuse version >= 2.70.0, < 2.95.11version >= 3.0.0, < 3.124.1 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.0 CVSS 3.1 Medium 3.1 1.4 security-advisories@github.com via NIST National Vulnerability Database
5.0 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N (score shown at the top: security-advisories@github.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-202

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.34%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · langfuse/langfuse
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.0
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2025
  • CVE published
    Nov 10, 2025 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

6 on the record

Elsewhere on this site

Langfuse
every CVE for this vendor
CWE-202
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-41487 Langfuse: Improper role-based-access control in Langfuse LLM connection management allowed users of role “member” to retrieve stored LLM provider API keys May 8, 2026
  • CVE-2026-24055 Langfuse Slack OAuth Installation Endpoint Lacks Authentication, Enabling Arbitrary Project Linking Jan 22, 2026
  • CVE-2025-65107 Langfuse SSO Account Takeover via CSRF or phishing attack Nov 21, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2025-64504 is "Langfuse vulnerable to cross‑organization enumeration of member & invitation lists via project membership APIs", rated Medium. It affects Langfuse (Langfuse); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.0 describes technical severity. EPSS 0.34% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.