How severe is CVE-2023-39954?

CVE-2023-39954 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2023-39954 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-39954?

CVE-2023-39954 affects Nextcloud User Oidc. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-39954?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-39954 published?

CVE-2023-39954 was published on 2023-08-10 and last updated on 2026-06-17.

CVE-2023-39954

CVE-2023-39954 is a low-severity vulnerability in Nextcloud User Oidc with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-311.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
EPSS exploit prediction: 0% (28th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-311
Affected product: Nextcloud User Oidc
Published: 2023-08-10
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2023-39954?: 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.
How severe is CVE-2023-39954?: CVE-2023-39954 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2023-39954 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (28th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-39954?: CVE-2023-39954 affects Nextcloud User Oidc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-39954?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-39954 published?: CVE-2023-39954 was published on 2023-08-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:user_oidc:*:*:*:*:*:*:*:*

More vulnerabilities in Nextcloud User Oidc

CVE-2023-32074 — High (CVSS 8.0): user_oidc app is an OpenID Connect user backend for Nextcloud. Authentication can be broken/bypassed in user_oidc app.…
CVE-2024-37312 — Medium (CVSS 6.3): user_oidc app is an OpenID Connect user backend for Nextcloud. Missing access control on the ID4me endpoint allows an…
CVE-2024-37886 — Medium (CVSS 5.4): user_oidc app is an OpenID Connect user backend for Nextcloud. An attacker could potentially trick the app into…
CVE-2023-39953 — Medium (CVSS 4.8): user_oidc provides the OIDC connect user backend for Nextcloud, an open-source cloud platform. Starting in version…
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