CVE-2026-18265: Missing Auth (CVSS 9.8)

Description

OSNEXUS QuantaStor Missing Authentication Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of OSNEXUS QuantaStor. Authentication is not required to exploit this vulnerability. The specific flaw exists within the configuration of Kapacitor. The issue results from the lack of authentication prior to allowing access to functionality. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-30036.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0069

Probability of exploitation

0.51%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-306 Missing Authentication

References

Other References

https://www.zerodayinitiative.com/advisories/ZDI-26-480/

Frequently Asked Questions

What is CVE-2026-18265? +

OSNEXUS QuantaStor Missing Authentication Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of OSNEXUS QuantaStor. Authentication is not required to exploit this vulnerability. The specific flaw exists within the configuration of Kapacitor. The issue results from the lack of authentication prior to allowing access to functionality. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-30036. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-18265? +

CVE-2026-18265 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0069, placing it in the 1th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-18265? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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