CVE-2023-45151 [Medium] | Security Vulnerability in Nextcloud Server

Nextcloud server is an open source home cloud platform. Affected versions of Nextcloud stored OAuth2 tokens in plaintext which allows an attacker who has gained access to the server to potentially elevate their privilege. This issue has been addressed and users are recommended to upgrade their Nextcloud Server to version 25.0.8, 26.0.3 or 27.0.1. There are no known workarounds for this vulnerability.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.69%	0.48%	-0.21%
2	2026-04-26	0.63%	0.69%	+0.06%
3	2026-03-04	—	0.63%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.69%

0.48%

-0.21%

2026-04-26

0.63%

0.69%

+0.06%

2026-03-04

—

0.63%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.5	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. 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:H) They need powerful rights—admin, root, or similar—before this pays off. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. 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:N) Service keeps running; no real outage angle.	1.2	5.2	[email protected]
8.8	3.1	HIGH	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. 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:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. 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.	2.8	5.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.5

3.1

MEDIUM

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:H): They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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:N): Service keeps running; no real outage angle.

1.2

5.2

[email protected]

8.8

3.1

HIGH

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

Attack vector (AV:N): Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
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:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
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.

2.8

5.9

[email protected]

Affected software / configurations for CVE-2023-45151

Vendor	Product	Version	Raw CPE
nextcloud	nextcloud_server	>= 25.0.0, < 25.0.8	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 25.0.0, < 25.0.8	cpe:2.3:a:nextcloud:nextcloud_server:::::enterprise:::*
nextcloud	nextcloud_server	>= 26.0.0, < 26.0.3	cpe:2.3:a:nextcloud:nextcloud_server:::::-:::*
nextcloud	nextcloud_server	>= 26.0.0, < 26.0.3	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-2023-45151

URL	Tags
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-hhgv-jcg9-p4m9	Vendor Advisory
https://github.com/nextcloud/server/pull/38398	Issue Tracking Patch
https://hackerone.com/reports/1994324	Permissions Required

URL

CVE-2023-45151 | OAuth2 client_secret stored in plain text in the Nextcloud database

Exploit prediction scoring system (EPSS) score for CVE-2023-45151

Common vulnerability scoring system (CVSS) metrics for CVE-2023-45151

Weakness enumeration for CVE-2023-45151

Affected software / configurations for CVE-2023-45151

References for CVE-2023-45151