Server-Side Request Forgery Vulnerability in Langfuse Webhook Handler
CVE-2025-9799

2.3LOW

Key Information:

Vendor

Langfuse

Status
Langfuse
Vendor
CVE Published:
1 September 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-9799?

A security flaw has been identified in the Langfuse application versions up to 3.88.0, specifically within the function promptChangeEventSourcing in the promptRouter.ts file. This vulnerability enables server-side request forgery, allowing potential attackers to manipulate server requests remotely. Although exploiting this vulnerability requires a high level of complexity, it poses a significant risk as the exploit has been publicly disclosed, increasing the likelihood of unauthorized access to sensitive server resources. It is crucial for users and organizations relying on Langfuse to implement necessary security measures to mitigate the potential impact.

Affected Version(s)

Langfuse 3.0

Langfuse 3.1

Langfuse 3.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-9799 - Proof of Concept

References

https://vuldb.com/?id.322114
vdb-entrytechnical-description
https://vuldb.com/?ctiid.322114
signaturepermissions-required
https://vuldb.com/?submit.641128
third-party-advisory

CVSS V4

Score:
2.3
Severity:
LOW
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ZAST.AI (VulDB User)
.