CVE-2025-66514

Description

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Prior to 5.5.3, a stored HTML injection in the Mail app's message list allowed an authenticated user to inject HTML into the email subjects. Javascript was correctly blocked by the content security policy of the Nextcloud Server code.

CVSS v3.1 Score

3.5

LOW

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

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
nextcloud	mail	< 5.5.3

References

Advisories & Patches

https://github.com/nextcloud/mail/commit/c64fcc3b79e0c089b5e1d2e04a07bfa740b2ac09 https://github.com/nextcloud/mail/pull/11740 https://github.com/nextcloud/security-advisories/security/advisories/GHSA-v394-8gpc-6fv5 https://hackerone.com/reports/3357036

Frequently Asked Questions

What is CVE-2025-66514? +

Nextcloud Mail is the mail app for Nextcloud, a self-hosted productivity platform. Prior to 5.5.3, a stored HTML injection in the Mail app's message list allowed an authenticated user to inject HTML into the email subjects. Javascript was correctly blocked by the content security policy of the Nextcloud Server code. It has a CVSS v3.1 base score of 3.5 (LOW).

How severe is CVE-2025-66514? +

CVE-2025-66514 has a CVSS v3.1 score of 3.5 out of 10, rated LOW. This is a low-severity vulnerability with limited impact.

What products are affected by CVE-2025-66514? +

CVE-2025-66514 affects products from nextcloud, specifically: mail. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-66514? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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