CVE-2025-66550 describes a medium-severity vulnerability in Nextcloud Calendar versions prior to 4.7.17 and 5.2.4. A malicious authenticated user could craft a calendar event with an attachment linking to a file on the same Nextcloud server, causing the file to download automatically without user confirmation. The vulnerability has a CVSS score of 5.7, indicating a low attack complexity and requiring user interaction, with a high impact on integrity but no impact on confidentiality or availability. There is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage regarding this CVE.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
>= 4.0.0, < 4.7.17CPE matchmatch criteria | cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:* | ||
>= 5.0.0, < 5.2.4CPE matchmatch criteria | cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.
No media coverage found for this CVE.
The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.