CVE-2026-68493: CWE-639 Insecure Direct Object Reference (IDOR) in Nextcloud Server
After guessing a 62^15 complex unique identifier, a malicious logged in user was able to retrieve a list of memberships for a circle they are not a member of.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-68493) in Nextcloud Server involves an IDOR issue (CWE-639) where a logged-in user, by guessing a 62^15 complexity unique identifier, can access membership lists of circles they are not authorized to view. The flaw affects Nextcloud Server versions from 32.0.0 up to and including 34.0.0. The CVSS 3.0 base score is 3.1, reflecting low impact with network attack vector, high attack complexity, low privileges required, no user interaction, and limited confidentiality impact only.
Potential Impact
An attacker with valid credentials can retrieve unauthorized membership information of circles they do not belong to. There is no impact on integrity or availability, and the confidentiality impact is limited to exposure of membership lists only. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Until a patch is available, cautious handling of circle membership information and monitoring for suspicious access patterns is advised.
CVE-2026-68493: CWE-639 Insecure Direct Object Reference (IDOR) in Nextcloud Server
Description
After guessing a 62^15 complex unique identifier, a malicious logged in user was able to retrieve a list of memberships for a circle they are not a member of.
CVSS v3.0
Score 3.1low
Affected software
Nextcloud
Server
pkg:github/nextcloud/serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-68493) in Nextcloud Server involves an IDOR issue (CWE-639) where a logged-in user, by guessing a 62^15 complexity unique identifier, can access membership lists of circles they are not authorized to view. The flaw affects Nextcloud Server versions from 32.0.0 up to and including 34.0.0. The CVSS 3.0 base score is 3.1, reflecting low impact with network attack vector, high attack complexity, low privileges required, no user interaction, and limited confidentiality impact only.
Potential Impact
An attacker with valid credentials can retrieve unauthorized membership information of circles they do not belong to. There is no impact on integrity or availability, and the confidentiality impact is limited to exposure of membership lists only. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Until a patch is available, cautious handling of circle membership information and monitoring for suspicious access patterns is advised.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- hackerone
- Date Reserved
- 2026-07-30T15:00:00.609Z
- Cvss Version
- 3.0
- State
- PUBLISHED
Threat ID: 6aad953b55bf5e2cf577b8a4
Added to database: 09/18/2026, 19:47:07 UTC
Last enriched: 09/18/2026, 20:02:33 UTC
Last updated: 09/19/2026, 02:00:04 UTC
Views: 6
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