CVE-2021-41239: nextcloud nextcloud_server
Vulnerability summary
CVE-2021-41239 is a medium (CVSS 5.3) vulnerability in nextcloud nextcloud_server. EPSS estimates a 1.13% chance of exploitation in the next 30 days, higher than 65.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 08-03-2022PublishedVulnerability first disclosed.
- 23-04-2025Last modifiedVulnerability information updated.
Description
Nextcloud server is a self hosted system designed to provide cloud style services. In affected versions the User Status API did not consider the user enumeration settings by the administrator. This allowed a user to enumerate other users on the instance, even when user listings where disabled. It is recommended that the Nextcloud Server is upgraded to 20.0.14, 21.0.6 or 22.2.1. There are no known workarounds.
CVSS metrics
3 scores · 2 sources · 2 versions- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
1.13%
Chance of exploitation in the next 30 days
Percentile
66%
Versus all other CVEs
30-day change
0.00 pp
From 1.13% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
- CWE-862Missing AuthorizationThe product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Affected systems
Nextcloud2 products
- nextcloud_serverEOL< 20.0.14 | ≥ 21.0.0, < 21.0.6 | 22.2.0
- security-advisories< 20.0.14 | ≥ 21.0.0, < 21.0.6 | ≥ 22.2.0, < 22.2.1
1 vendor · 2 products
References
4 links- github.com/nextcloud/security-advisories/security/advisories/GHSA-g722-cm3h-8wrxX Refsource CONFIRMIssue TrackingThird Party Advisory