CVE-2026-5320

Medium

Published: 02 April 2026

Published

02 April 2026

Modified

27 April 2026

KEV Added

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Patch

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CVSS Score v4 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Score 0.0008 24.0th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-5320 is a medium-severity Improper Authentication (CWE-287) vulnerability. Its CVSS base score is 6.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 24.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as NLP and Transformers; in the Supply Chain and Deployment risk domain.

The strongest mitigations our analysis identified are NIST 800-53 AC-3 (Access Enforcement) and SC-14 (Public Access Protections).

Deeper analysis

CVE-2026-5320 is a missing authentication vulnerability affecting vanna-ai vanna versions up to 2.0.2. The issue resides in an unknown functionality within the /api/vanna/v2/ file of the Chat API Endpoint component. Manipulation of this endpoint bypasses required authentication checks, as classified under CWE-287 (Improper Authentication) and CWE-306 (Missing Authentication for Critical Function). The vulnerability carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L) and was published on 2026-04-02.

Remote attackers require no privileges or user interaction to exploit this vulnerability over the network with low complexity. Successful exploitation grants limited impact on confidentiality, integrity, and availability, potentially allowing unauthorized access to chat API functions.

Advisories reference disclosure details but note that the vendor was contacted early without any response, and no patches or mitigations are mentioned. Relevant URLs include https://github.com/August829/CVEP/issues/13, https://vuldb.com/submit/780727, https://vuldb.com/vuln/354652, and https://vuldb.com/vuln/354652/cti.

The exploit is public and publicly available for use, with vanna-ai's AI-driven nature potentially exposing deployments in data querying or analytics environments to unauthorized API interactions.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-18120

Vulnerability details

A vulnerability was detected in vanna-ai vanna up to 2.0.2. Affected by this vulnerability is an unknown functionality of the file /api/vanna/v2/ of the component Chat API Endpoint. Performing a manipulation results in missing authentication. The attack can be initiated…

remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

CWE(s): CWE-287 CWE-306

AI Security AnalysisAI

AI Category: NLP and Transformers
Risk Domain: Supply Chain and Deployment
OWASP Top 10 for LLMs 2025: None mapped
Classification Reason: Matched keywords: ai

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

Why these techniques?

Missing authentication vulnerability in public-facing Chat API endpoint directly enables remote exploitation without credentials, mapping to T1190 for initial access to the application.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1