Critical exploit reference

CVE-2026-40525 — OpenViking < 0.3.9 Authentication Bypass via VikingBot OpenAPI

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 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.

Published Apr 17, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.8% (30-day exploitation probability)+8
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.76%

ahead of 54% of scored CVEs · Oct 14, 2026

Affects

Volcengine

Openviking

CVSS base

9.1

Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)
Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Volcengine Openviking).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Volcengine	Openviking	< 0.3.9	Vulnerable	NIST National Vulnerability Database
Volcengine	Openviking	< 0.3.9	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.1	CVSS 4.0	Critical	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
9.1	CVSS 4.0	Critical	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
9.1	CVSS 3.1	Critical	3.9	5.2	disclosure@vulncheck.com via NIST National Vulnerability Database
9.1	CVSS 3.1	Critical	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-636

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.76%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).

web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

2026
Affected products added · volcengine/openviking
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.1
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Apr 17, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

github.com/volcengine/OpenViking/pull/1447
Exploit, Patch, Vendor Advisory, issue-tracking, NIST National Vulnerability Database
github.com/volcengine/OpenViking/commit/c7bb1676f4d037609f041bf39e4e2bd52e8f9820
Patch, patch, NIST National Vulnerability Database
www.vulncheck.com/advisories/openviking-authentication-bypass-via-vikingbot-openapi
Third Party Advisory, third-party-advisory, NIST National Vulnerability Database
github.com/volcengine/OpenViking/releases/tag/v0.3.9
Release Notes, release-notes, NIST National Vulnerability Database

Elsewhere on this site

Volcengine
every CVE for this vendor

CWE-636
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-22681 OpenViking < 0.3.4 SSRF via /api/v1/resources Aug 21, 2026
Medium CVE-2026-13507 volcengine OpenViking Local VectorDB Primary-key Label str_to_uint64.py str_to_uint64 data authenticity Jun 28, 2026
Medium CVE-2026-22680 OpenViking < 0.3.3 Missing Authorization via Task Polling Apr 7, 2026
Medium CVE-2026-34999 OpenViking 0.2.5 < 0.2.14 Bot Proxy Endpoints Allow Unauthenticated Access Apr 1, 2026
High CVE-2026-28518 OpenViking .ovpack Import ZIP Slip Path Traversal Mar 3, 2026
Critical CVE-2026-22207 OpenViking Missing root_api_key Allows Anonymous ROOT Access Feb 26, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-40525 is "OpenViking < 0.3.9 Authentication Bypass via VikingBot OpenAPI", rated Critical. It affects Openviking (Volcengine); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.1 describes technical severity. EPSS 0.76% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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