How severe is CVE-2023-23943?

CVE-2023-23943 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2023-23943 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-23943?

CVE-2023-23943 affects Nextcloud Mail. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-23943?

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

When was CVE-2023-23943 published?

CVE-2023-23943 was published on 2023-02-06 and last updated on 2026-06-17.

CVE-2023-23943

CVE-2023-23943 is a medium-severity vulnerability in Nextcloud Mail with a CVSS 3.x base score of 5.0. 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-918.

Key facts

Severity: Medium (CVSS 3.x base score 5.0)
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-918
Affected product: Nextcloud Mail
Published: 2023-02-06
Last modified: 2026-06-17

Description

Nextcloud mail is an email app for the nextcloud home server platform. In affected versions the SMTP, IMAP and Sieve host fields allowed to scan for internal services and servers reachable from within the local network of the Nextcloud Server. It is recommended that the Nextcloud Maill app is upgraded to 1.15.0 or 2.2.2. The only known workaround for this issue is to completely disable the nextcloud mail app.

Frequently asked questions

What is CVE-2023-23943?: Nextcloud mail is an email app for the nextcloud home server platform. In affected versions the SMTP, IMAP and Sieve host fields allowed to scan for internal services and servers reachable from within the local network of the Nextcloud Server. It is recommended that the Nextcloud Maill app is upgraded to 1.15.0 or 2.2.2. The only known workaround for this issue is to completely disable the nextcloud mail app.
How severe is CVE-2023-23943?: CVE-2023-23943 has a CVSS 3.x base score of 5.0, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-23943 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-23943?: CVE-2023-23943 affects Nextcloud Mail. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-23943?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-23943 published?: CVE-2023-23943 was published on 2023-02-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:mail:*:*:*:*:*:*:*:*

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