How severe is CVE-2025-30276?

CVE-2025-30276 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-30276 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-30276?

CVE-2025-30276 affects Qnap Qsync Central. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-30276?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-30276 have an EU (EUVD) identifier?

Yes. CVE-2025-30276 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207454.

When was CVE-2025-30276 published?

CVE-2025-30276 was published on 2026-02-11 and last updated on 2026-06-17.

CVE-2025-30276

CVE-2025-30276 is a high-severity vulnerability in Qnap Qsync Central with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 4.9
EPSS exploit prediction: 1% (39th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-207454
Weakness: CWE-787
Affected product: Qnap Qsync Central
Published: 2026-02-11
Last modified: 2026-06-17

Description

An out-of-bounds write vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to modify or corrupt memory. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 ( 2026/01/20 ) and later

Frequently asked questions

What is CVE-2025-30276?: An out-of-bounds write vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to modify or corrupt memory. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 ( 2026/01/20 ) and later
How severe is CVE-2025-30276?: CVE-2025-30276 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-30276 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-30276?: CVE-2025-30276 affects Qnap Qsync Central. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-30276?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-30276 have an EU (EUVD) identifier?: Yes. CVE-2025-30276 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-207454.
When was CVE-2025-30276 published?: CVE-2025-30276 was published on 2026-02-11 and last updated on 2026-06-17.

References

https://www.qnap.com/en/security-advisory/qsa-26-02

Affected products (1)

cpe:2.3:a:qnap:qsync_central:*:*:*:*:*:*:*:*

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