Vulnerability · CVE-2025-64011
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint.
Published Dec 12, 2025 · catalog updated Oct 14, 2026 · nextcloud server
Check if you run it
No confirmed exploitation is on record for CVE-2025-64011. EPSS is 0.27%. Act only if a listed version of nextcloud server is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium4.3
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.27%
- Remediation
- Not established
- Affected products
- cpe nextcloud/nextcloud server
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe nextcloud/nextcloud server30.0.0
How to fix CVE-2025-64011
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2025-64011. EPSS is 0.27%. Act only if a listed version of nextcloud server is installed.
Which versions are affected?
Compare what you have installed with nextcloud/nextcloud server 30.0.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-639: Authorization Bypass Through User-Controlled Key. EPSS 0.27%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Dec 12, 2025 · NIST NVD
Detected
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.
Oct 14, 2026 · NIST NVD
Updated
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of sensitive data, such as text files or images, without prior sharing permissions.
Sources
- CVE.orgVulnerability recordCVE-2025-64011
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-64011
30-day exploitation probability 0.3%
first.org - NIST NVDVulnerability recordCVE-2025-64011
Nextcloud Server 30.0.0 is vulnerable to an Insecure Direct Object Reference (IDOR) in the /core/preview endpoint. Any authenticated user can access previews of arbitrary files belonging to other users by manipulating the fileId parameter. This allows unauthorized disclosure of s
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.