How severe is CVE-2025-66593?

CVE-2025-66593 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2025-66593 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66593?

CVE-2025-66593 affects Synology Assistant. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66593?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-66593 have an EU (EUVD) identifier?

Yes. CVE-2025-66593 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209963.

When was CVE-2025-66593 published?

CVE-2025-66593 was published on 2026-05-27 and last updated on 2026-06-17.

CVE-2025-66593

CVE-2025-66593 is a medium-severity vulnerability in Synology Assistant with a CVSS 3.x base score of 6.1. 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-346.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-209963
Weakness: CWE-346
Affected product: Synology Assistant
Published: 2026-05-27
Last modified: 2026-06-17

Description

An origin validation error vulnerability in Synology Assistant before 7.0.6-50085 allows local users to write arbitrary files with restricted content and conduct denial-of-service during installation.

Frequently asked questions

What is CVE-2025-66593?: An origin validation error vulnerability in Synology Assistant before 7.0.6-50085 allows local users to write arbitrary files with restricted content and conduct denial-of-service during installation.
How severe is CVE-2025-66593?: CVE-2025-66593 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2025-66593 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66593?: CVE-2025-66593 affects Synology Assistant. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66593?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66593 have an EU (EUVD) identifier?: Yes. CVE-2025-66593 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-209963.
When was CVE-2025-66593 published?: CVE-2025-66593 was published on 2026-05-27 and last updated on 2026-06-17.

References

https://www.synology.com/en-global/security/advisory/Synology_SA_25_17

Affected products (1)

cpe:2.3:a:synology:assistant:*:*:*:*:*:*:*:*

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