CVE-2026-40525: OpenViking: Unauthenticated remote bot control via OpenAPI HTTP routes

Should you act?

Critical and remotely reachable

No known exploitation yet, but it is network-reachable without credentials. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

• No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
• EPSS 0.8%, percentile 55: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 55% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
• Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
• Only applies if your dependency tree includes openviking (PyPI) < 0.3.9, fixed in 0.3.9. Check your lockfile, including transitive dependencies.

What it is

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 apikey configuration value is unset or empty. Remote attackers with network access to the exposed 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.

From the GitHub advisory

OpenViking prior to commit c7bb167 contains an authentication bypass vulnerability in the VikingBot OpenAPI HTTP route surface where the authentication check fails open when the apikey configuration value is unset or empty. Remote attackers with network access to the exposed 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.

Weakness type: CWE-636.

Product: openviking (PyPI) · Assigned by: VulnCheck · Published: 2026-04-17

Affected and fixed versions

Severity scores

• Attack vector: network (remotely reachable)
• Attack complexity: low
• Attack requirements: present (depends on deployment conditions)
• Privileges required: none (no login)
• User interaction: none

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

• CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
• CISA SSVC assessment: exploitation none, automatable yes, technical impact total.
• FIRST EPSS (model of 2026-10-21): 0.76% probability of exploitation activity in the next 30 days; percentile 55.

Timeline

• 2026-04-17 — CVE record published by VulnCheck
• 2026-04-17 — GitHub-reviewed advisory GHSA-jgq2-vq69-gr6h published (critical)
• 2026-10-08 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

1. github.com github.com
2. github.com github.com

Vulnerability records

1. GitHub Advisory GHSA-jgq2-vq69-gr6h github.com
2. CVE.org record CVE-2026-40525 cve.org
3. NVD entry CVE-2026-40525 nvd.nist.gov

Other references from the CVE record and advisory

1. github.com github.com
2. vulncheck.com vulncheck.com

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