SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-66546

Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token.

LOW 3.3EPSS 0.14%

Does this matter?

Lower severity and a low EPSS score (0.14%). Track it; it rarely justifies an emergency change on its own.

Description

Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.

CVSS 3.1
3.3 LOWCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS
0.14% probability · 4th percentile
CISA KEV
Not listed
Weakness
CWE-639
Affected
nextcloud/calendar
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.