What is CVE-2023-45660?

CVE-2023-45660 is a medium-severity vulnerability in Nextcloud Mail, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.3/10. Published 2023-10-16.

How severe is CVE-2023-45660?

Medium severity. CVSS v3 base score is 4.3 out of 10.

SSRF in Nextcloud Mail

CVE-2023-45660

Nextcloud mail is an email app for the Nextcloud home server platform. In affected versions a missing check of origin, target and cookies allows for an attacker to abuse the proxy endpoint to denial of service a third server. It is recommended that the Nextcloud Mail is upgraded to 2.2.8 or 3.3.0. There are no known workarounds for this vulnerability.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published 2023-10-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.006 (46.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Nextcloud Mail
Nextcloud Security-Advisories — versions >= 2.0.0, < 2.2.8, >= 3.0.0, < 3.3.0

Weakness classification (CWE)

CWE-918 — Server-Side Request Forgery (SSRF)

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-8j9x-fmww-qr37 (Vendor Advisory)
github.com/nextcloud/mail/pull/8459 (Patch, Issue Tracking)
hackerone.com/reports/1895874 (Third Party Advisory)

Frequently asked questions

What is CVE-2023-45660?: CVE-2023-45660 is a medium-severity vulnerability in Nextcloud Mail, classified under Server-Side Request Forgery (SSRF). CVSS score: 4.3/10. Published 2023-10-16.
How severe is CVE-2023-45660?: Medium severity. CVSS v3 base score is 4.3 out of 10.