CVE-2023-39963 | Missing password confirmation when creating app passwords

Nextcloud Server provides data storage for Nextcloud, an open source cloud platform. Starting in version 20.0.0 and prior to versions 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.8, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1, a missing password confirmation allowed an attacker, after successfully stealing a session from a logged in user, to create app passwords for the victim. Nextcloud server versions 25.0.9, 26.0.4, and 27.0.1 and Nextcloud Enterprise Server versions 20.0.14.15, 21.0.9.13, 22.2.10.14, 23.0.12.9, 24.0.12.5, 25.0.9, 26.0.4, and 27.0.1 contain a patch for this issue. No known workarounds are available.

Published: 2023-08-10 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-39963 is rated Moderate Risk (44.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.15%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-39963

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 0.14% 0.15% +0.02%
2 2025-11-21 0.04% 0.14% +0.10%
3 2025-11-18 — 0.04% —

Full EPSS history (9 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-39963

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 1.5 6.0 [email protected]
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]

Weakness enumeration for CVE-2023-39963

Affected software / configurations for CVE-2023-39963

Vendor Product Version Raw CPE
nextcloud nextcloud_server >= 20.0.0, < 20.0.14.15 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 21.0.0, < 21.0.9.13 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 22.0.0, < 22.2.10.14 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 23.0.0, < 23.0.12.9 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 24.0.0, < 24.0.12.5 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 25.0.0, < 25.0.9 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*
nextcloud nextcloud_server >= 25.0.0, < 25.0.9 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server >= 26.0.0, < 26.0.4 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:*
nextcloud nextcloud_server >= 26.0.0, < 26.0.4 cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:*
nextcloud nextcloud_server 27.0.0 cpe:2.3:a:nextcloud:nextcloud_server:27.0.0:*:*:*:-:*:*:*
nextcloud nextcloud_server 27.0.0 cpe:2.3:a:nextcloud:nextcloud_server:27.0.0:*:*:*:enterprise:*:*:*

References for CVE-2023-39963

cvelogic Threat Intelligence