How severe is CVE-2025-66557?

CVE-2025-66557 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.

Is CVE-2025-66557 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-66557?

CVE-2025-66557 affects Nextcloud Deck. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-66557?

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

Does CVE-2025-66557 have an EU (EUVD) identifier?

Yes. CVE-2025-66557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201465.

When was CVE-2025-66557 published?

CVE-2025-66557 was published on 2025-12-05 and last updated on 2026-06-17.

CVE-2025-66557

CVE-2025-66557 is a medium-severity vulnerability in Nextcloud Deck with a CVSS 3.x base score of 5.4. 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-284.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (15th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-201465
Weakness: CWE-284
Affected product: Nextcloud Deck
Published: 2025-12-05
Last modified: 2026-06-17

Description

Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. This vulnerability is fixed in 1.14.6 and 1.15.2.

Frequently asked questions

What is CVE-2025-66557?: Nextcloud Deck is a kanban style organization tool aimed at personal planning and project organization for teams integrated with Nextcloud. Prior to 1.14.6 and 1.15.2, a bug in the permission logic allowed users with "Can share" permission to modify the permissions of other recipients. This vulnerability is fixed in 1.14.6 and 1.15.2.
How severe is CVE-2025-66557?: CVE-2025-66557 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
Is CVE-2025-66557 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-66557?: CVE-2025-66557 affects Nextcloud Deck. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-66557?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-66557 have an EU (EUVD) identifier?: Yes. CVE-2025-66557 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-201465.
When was CVE-2025-66557 published?: CVE-2025-66557 was published on 2025-12-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:deck:*:*:*:*:*:*:*:*

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