CVE-2018-3761
Nextcloud Server before 12.0.8 and 13.0.3 suffer from improper authentication on the OAuth2 token endpoint.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.66%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- EPSS
- 1.66% probability · 76th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-287
- Affected
- nextcloud/nextcloud server
- Source
- support@hackerone.com
EPSS 1.7% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://hackerone.com/reports/343111Third Party Advisory
- https://nextcloud.com/security/advisory/?id=nc-sa-2018-003Broken Link, Vendor Advisory
- https://hackerone.com/reports/343111Third Party Advisory
- https://nextcloud.com/security/advisory/?id=nc-sa-2018-003Broken Link, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.