CVE-2022-39338 | Stored cross site scripting (XSS) vulnerability via Authorization Endpoint in user_oidc

user_oidc is an OpenID Connect user backend for Nextcloud. Versions prior to 1.2.1 did not properly validate discovery urls which may lead to a stored cross site scripting attack vector. The impact is limited due to the restrictive CSP that is applied on this endpoint. Additionally this vulnerability has only been shown to be exploitable in the Safari web browser. This issue has been addressed in version 1.2.1. Users are advised to upgrade. Users unable to upgrade should urge their users to avoid using the Safari web browser.

Published: 2022-11-25 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-39338 is rated Low Risk (29.4/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.58%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2022-39338

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 2026-06-15 0.28% 0.58% +0.30%
2 2026-06-11 0.36% 0.28% -0.08%
3 2026-05-21 — 0.36% —

Full EPSS history (23 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-39338

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.5 3.1 LOW
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/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: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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 0.9 2.5 [email protected]
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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: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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.3 2.7 [email protected]

Weakness enumeration for CVE-2022-39338

Affected software / configurations for CVE-2022-39338

Vendor Product Version Raw CPE
nextcloud openid_connect_user_backend < 1.2.1 cpe:2.3:a:nextcloud:openid_connect_user_backend:*:*:*:*:*:nextcloud:*:*

References for CVE-2022-39338

cvelogic Threat Intelligence