Cross-Domain Policy Flaw in vanna-ai's FastAPI/Flask Server
CVE-2026-5321

5.3MEDIUM

Key Information:

Vendor

Vanna-ai

Status
Vanna
Vendor
CVE Published:
2 April 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-5321?

A vulnerability exists in vanna-ai's vanna application, specifically impacting versions up to 2.0.2. This issue arises from an insecure configuration in the FastAPI/Flask Server component, allowing attackers to manipulate the cross-domain policy. Such manipulation can result in permissive access to untrusted domains. The remote exploit poses a significant risk as it facilitates unauthorized data sharing across domains. Reports indicate that the vendor was alerted regarding this vulnerability but did not provide a response.

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Affected Version(s)

vanna 2.0.0

vanna 2.0.1

vanna 2.0.2

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-2026-5321 - Proof of Concept

References

https://vuldb.com/vuln/354653
vdb-entry
https://vuldb.com/vuln/354653/cti
signaturepermissions-required
https://vuldb.com/submit/780729
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Yu_Bao (VulDB User)
VulDB
JSON
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