CVE-2023-23943

Name: CVE-2023-23943
Creator: NVD / NIST
Published: 2023-02-06T21:15:09.81+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.3/10EPSS 0.92%

Last modified Jun 17, 2026

CVE-2023-23943 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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. EPSS estimates a 0.92% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

4.3/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS Probability

0.92%

55.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-918

Affected Software

Vendor	Product	Versions
Nextcloud	Mail	< 1.15.0
Nextcloud	Mail	>= 2.2.0, < 2.2.2

References

https://github.com/nextcloud/mail/pull/7796Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8gcx-r739-9pf6Vendor Advisory
https://hackerone.com/reports/1736390Exploit, Third Party Advisory
https://hackerone.com/reports/1741525Exploit, Third Party Advisory
https://hackerone.com/reports/1746582Exploit, Third Party Advisory
https://github.com/nextcloud/mail/pull/7796Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8gcx-r739-9pf6Vendor Advisory
https://hackerone.com/reports/1736390Exploit, Third Party Advisory
https://hackerone.com/reports/1741525Exploit, Third Party Advisory
https://hackerone.com/reports/1746582Exploit, Third Party Advisory

Timeline

Published: Feb 6, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-23943?

How severe is CVE-2023-23943?

CVE-2023-23943 has a CVSS score of 4.3/10 (MEDIUM severity). The EPSS model estimates a 0.92% probability of exploitation in the next 30 days.

How do I fix CVE-2023-23943?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-23943?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST