Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9 suffer from SMB User Authentication Bypass. Nextcloud/ownCloud include an optional and not by default enabled SMB authentication component that allows authenticating users against an SMB server. This backend is implemented in a way that tries to connect to a SMB server and if that succeeded consider the user logged-in. The backend did not properly take into account SMB servers that have any kind of anonymous auth configured. This is the default on SMB servers nowadays and allows an unauthenticated attacker to gain access to an account without valid credentials. Note: The SMB backend is disabled by default and requires manual configuration in the Nextcloud/ownCloud config file. If you have not configured the SMB backend then you're not affected by this vulnerability.
CVE-2016-9463
HIGHNVD 8.18.1—
EchelonGraph scoreMEDIUM confidence
Score 8.1 from GitHub Security Advisory (severity: HIGH) published 2022-05-13. NVD baseline CVSS 8.1; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 4%CVSS: 8.1Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 8.1
- EG Score
- 8.1(medium)
- EPSS
- 89.5%
- KEV
- Not listed
Published
March 28, 2017
Last Modified
May 13, 2026
References (18)
- support@hackeronehttps://github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274
- support@hackeronehttps://github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087
- support@hackeronehttps://github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791
- support@hackeronehttps://github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732
- support@hackeronehttps://github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3
- support@hackeronehttps://hackerone.com/reports/148151
- support@hackeronehttps://nextcloud.com/security/advisory/?id=nc-sa-2016-006
- support@hackeronehttps://owncloud.org/security/advisory/?id=oc-sa-2016-017
- support@hackeronehttps://rhinosecuritylabs.com/2016/10/operation-ownedcloud-exploitation-post-exploitation-persistence/
- af854a3a-2127-422b-91ae-364da2661108https://github.com/nextcloud/apps/commit/b85ace6840b8a6704641086bc3b8eb8e81cb2274
- af854a3a-2127-422b-91ae-364da2661108https://github.com/nextcloud/apps/commit/decb91fd31f4ffab191cbf09ce4e5c55c67a4087
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/apps/commit/16cbccfc946c8711721fa684d78135ca1fb64791
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/apps/commit/5d47e7b52646cf79edadd78ce10c754290cbb732
- af854a3a-2127-422b-91ae-364da2661108https://github.com/owncloud/apps/commit/a0e07b7ddd5a5fd850a6e07f8457d05b76a300b3
- af854a3a-2127-422b-91ae-364da2661108https://hackerone.com/reports/148151
Data Freshness Timeline
(refreshed 10× in last 7d / 35× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
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Frequently asked(5)
What is CVE-2016-9463?
CVE-2016-9463 is a high vulnerability published on March 28, 2017. Nextcloud Server before 9.0.54 and 10.0.1 & ownCloud Server before 9.1.2, 9.0.6, and 8.2.9 suffer from SMB User Authentication Bypass. Nextcloud/ownCloud include an optional and not by default enabled SMB authentication component that allows authenticating users against an SMB server. This backend…
When was CVE-2016-9463 disclosed?
CVE-2016-9463 was first published in the National Vulnerability Database on March 28, 2017, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2016-9463 actively exploited?
CVE-2016-9463 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 89.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2016-9463?
CVE-2016-9463 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2016-9463?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2016-9463, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2016-9463
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