CVE-2018-3761
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token...
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
- Record
CVE-2018-3761- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:P/I:P/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
CVE List No score
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
- Record
CVE-2018-3761- Weakness
- CWE-287
- Updated
- 2026-11-02
EUVDEUVD-2018-15567 No score
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
- Record
EUVD-2018-15567- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-frc3-rhfw-jxf5
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token...
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
- Record
GHSA-frc3-rhfw-jxf5- CVSS 3.0
- 8.1 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Weakness
- CWE-287
- Updated
- 2026-11-02
OSV
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint. Missing checks potentially allowed handing out new tokens in case the OAuth2 client was partly compromised.
- Record
CVE-2018-3761- CVSS 3.1
- 8.1 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, products | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-3761 is a high vulnerability (CVSS 8.1) in Hackerone Nextcloud Server, published July 5, 2018. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.66%, the 76th percentile. No source names a fixed version.