Vulnerability record · CVE-2023-39954 · published 10 August 2023

CVE-2023-39954: Nextcloud user oidc missing encryption vulnerability

Nextcloud · User Oidc

user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version 1.0.0 and prior to version 1.3.3, an attacker that obtained at least read access to a snapshot of the database can impersonate the Nextcloud server towards linked servers. user_oidc 1.3.3 contains a patch. No known workarounds are available.

8.1 CVSS 3.1 High EPSS 0.44% · top 63.9% CWE-311 · Missing encryption

8.1CVSS 3.1 base score

0.44%EPSS exploitation probability, 30 days

NoNot in CISA KEV

1Affected product versions listed by NVD

6References

17 Jun 2026Last modified by NVD

Description

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

User Oidc Nextcloud

References

Link	Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3f92-5c8p-f6gq	PatchVendor Advisory
https://github.com/nextcloud/user_oidc/pull/636	Patch
https://hackerone.com/reports/1994328	Permissions Required
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-3f92-5c8p-f6gq	PatchVendor Advisory
https://github.com/nextcloud/user_oidc/pull/636	Patch
https://hackerone.com/reports/1994328	Permissions Required

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2023-32074Nextcloud user oidc improper restriction of authentication attempts vulnerabilityuser_oidc app is an OpenID Connect user backend for Nextcloud. Authentication can be broken/bypassed in user_oidc app. It is recommended that the Nex…EPSS 0.85%25 May 2023 8.8CVE-2026-45284Nextcloud user oidc improper access control vulnerabilityNextcloud is an open source content collaboration platform. From version 1.3.6 to before version 8.4.0, an improper check allowed users that where pr…EPSS 0.36%1 Jun 2026 6.3CVE-2024-37312Nextcloud user oidc improper access control vulnerabilityuser_oidc app is an OpenID Connect user backend for Nextcloud. Missing access control on the ID4me endpoint allows an attacker to register an account…EPSS 0.64%14 Jun 2024 6.1CVE-2026-45278Nextcloud user oidc open redirect vulnerabilityNextcloud is an open source content collaboration platform. From version 6.1.0 to before version 8.2.2, an attacker can craft links that would redire…EPSS 0.32%1 Jun 2026 6.1CVE-2024-52512Nextcloud user oidc open redirect vulnerabilityuser_oidc app is an OpenID Connect user backend for Nextcloud. A malicious user could send a malformed login link that would redirect the user to a p…EPSS 0.42%15 Nov 2024 5.4CVE-2023-28848Nextcloud user oidc cross-site request forgery vulnerabilityuser_oidc is the OIDC connect user backend for Nextcloud, an open source collaboration platform. A vulnerability in versions 1.0.0 until 1.3.0 effect…EPSS 0.33%4 Apr 2023 4.8CVE-2023-39953Nextcloud user oidc vulnerabilityuser_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version 1.0.0 and prior to version 1.3.3, …EPSS 0.54%10 Aug 2023 4.7CVE-2024-37886Nextcloud user oidc improper verification of cryptographic signature vulnerabilityuser_oidc app is an OpenID Connect user backend for Nextcloud. An attacker could potentially trick the app into accepting a request that is not signe…EPSS 0.24%14 Jun 2024

Source: NIST National Vulnerability Database (record CVE-2023-39954), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.