How severe is CVE-2023-39955?

CVE-2023-39955 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2023-39955 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-39955?

CVE-2023-39955 affects Nextcloud Notes. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-39955?

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

When was CVE-2023-39955 published?

CVE-2023-39955 was published on 2023-08-10 and last updated on 2026-06-17.

CVE-2023-39955

CVE-2023-39955 is a low-severity vulnerability in Nextcloud Notes with a CVSS 3.x base score of 3.5. 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-79.

Key facts

Severity: Low (CVSS 3.x base score 3.5)
EPSS exploit prediction: 0% (38th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Nextcloud Notes
Published: 2023-08-10
Last modified: 2026-06-17

Description

Notes is a note-taking app for Nextcloud, an open-source cloud platform. Starting in version 4.4.0 and prior to version 4.8.0, when creating a note file with HTML, the content is rendered in the preview instead of the file being offered to download. Nextcloud Notes app version 4.8.0 contains a patch for the issue. No known workarounds are available.

Frequently asked questions

What is CVE-2023-39955?: Notes is a note-taking app for Nextcloud, an open-source cloud platform. Starting in version 4.4.0 and prior to version 4.8.0, when creating a note file with HTML, the content is rendered in the preview instead of the file being offered to download. Nextcloud Notes app version 4.8.0 contains a patch for the issue. No known workarounds are available.
How severe is CVE-2023-39955?: CVE-2023-39955 has a CVSS 3.x base score of 3.5, rated low severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2023-39955 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (38th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-39955?: CVE-2023-39955 affects Nextcloud Notes. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-39955?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-39955 published?: CVE-2023-39955 was published on 2023-08-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:notes:*:*:*:*:*:nextcloud:*:*

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