CVE-2025-66515: nextcloud approval Improper Authentication
Vulnerability summary
CVE-2025-66515 is a low (CVSS 2.7) Improper Authentication vulnerability in nextcloud approval. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.6% of scored vulnerabilities.
Timeline
- 05-12-2025PublishedVulnerability first disclosed.
- 05-12-2025Last modifiedVulnerability information updated.
Description
The Nextcloud Approval app allows approval or disapproval of files in the sidebar. Prior to 1.3.1 and 2.5.0, an authenticated user listed as a requester in a workflow can set another user’s file into the “pending approval” without access to the file by using the numeric file id. This vulnerability is fixed in 1.3.1 and 2.5.0.
CVSS metrics
2 scores · 2 sources · 1 version- NVDNIST2.7LowCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
EPSS trend
Probability
0.31%
Chance of exploitation in the next 30 days
Percentile
23%
Versus all other CVEs
30-day change
0.00 pp
From 0.31% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Nextcloud2 products
- approval≥ 1.0.0, < 1.3.1 | ≥ 2.0.0, < 2.5.0
- security-advisories≥ 2.0.0, < 2.5.0 | < 1.3.1
1 vendor · 2 products
References
4 links- github.com/nextcloud/security-advisories/security/advisories/GHSA-q26g-fmjq-x5g5X Refsource CONFIRMPatchVendor Advisory