Is CVE-2023-39303 actively exploited?

No active exploitation of CVE-2023-39303 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2023-39303 be exploited remotely?

Yes. CVE-2023-39303 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2023-39303?

CVE-2023-39303 has a CVSS score of 9.8 (CRITICAL).

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CRITICAL

CVE-2023-39303

CWE-287Published: February 2, 2024· Updated: Jun 17, 2026

9.8

CVSS v3.1

Official Description

An improper authentication vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to compromise the security of the system via a network.

We have already fixed the vulnerability in the following versions:

QTS 5.1.3.2578 build 20231110 and later

QuTS hero h5.1.3.2578 build 20231110 and later

QuTScloud c5.1.5.2651 and later

NVD Source

Risk Analysis

An improper authentication vulnerability in QNAP operating systems allows attackers to compromise system security remotely. This critical issue carries a CVSS score of 9.8.

There is no known public exploit for this vulnerability, and it is not in the CISA KEV. It is remotely exploitable.

Recommended Action

Update QTS, QuTS hero, or QuTScloud to the versions listed in the vendor security advisory.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2023-39303 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

From a weakness classification perspective (CWE-287): Authentication bypass vulnerabilities allow attackers to access protected resources without valid credentials.