Cyber Posture

CVE-2026-40525

CriticalPublic PoC

Published: 17 April 2026

Published
17 April 2026
Modified
05 May 2026
KEV Added
Patch
CVSS Score 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0029 52.6th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Description

OpenViking prior to version 0.3.9 contains an authentication bypass vulnerability in the VikingBot OpenAPI HTTP route surface where the authentication check fails open when the api_key configuration value is unset or empty. Remote attackers with network access to the exposed…

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service can invoke privileged bot-control functionality without providing a valid X-API-Key header, including submitting attacker-controlled prompts, creating or using bot sessions, and accessing downstream tools, integrations, secrets, or data accessible to the bot.

Mitigating Controls (NIST 800-53 r5)AI

prevent

Enforces approved authorizations for logical access to privileged bot-control functionality, directly preventing the authentication bypass vulnerability in OpenAPI routes.

prevent

Mandates secure configuration settings like a valid api_key to ensure authentication checks do not fail open when unset or empty.

prevent

Requires timely flaw remediation through patching to OpenViking version 0.3.9, which fixes the authentication bypass via commit c7bb1676f4d037609f041bf39e4e2bd52e8f9820.

Security SummaryAI

CVE-2026-40525 is an authentication bypass vulnerability (CWE-636) in OpenViking versions prior to 0.3.9. The flaw exists in the VikingBot OpenAPI HTTP route surface, where the authentication check fails in an open state when the api_key configuration value is unset or empty. This allows unauthorized access to privileged functionality without a valid X-API-Key header.

Remote attackers with network access to an exposed OpenViking instance can exploit the vulnerability with low complexity and no privileges required. Successful exploitation enables invocation of bot-control features, such as submitting attacker-controlled prompts, creating or using bot sessions, and accessing downstream tools, integrations, secrets, or data available to the bot. The issue carries a CVSS v3.1 base score of 9.1 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N), indicating high confidentiality and integrity impacts.

Mitigation involves upgrading to OpenViking version 0.3.9 or later, which incorporates the fix via GitHub commit c7bb1676f4d037609f041bf39e4e2bd52e8f9820 and pull request #1447. Additional guidance is provided in the VulnCheck advisory at https://www.vulncheck.com/advisories/openviking-authentication-bypass-via-vikingbot-openapi.

Details

CWE(s)

Affected Products

volcengine
openviking
≤ 0.3.9

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.
Why these techniques?

The vulnerability is an authentication bypass in a public-facing OpenAPI HTTP service, directly enabling remote exploitation of a public-facing application without authentication.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References