CVE-2023-45150

Inviting excessive long email addresses to a calendar event makes the Nextcloud server unresponsive

MEDIUM
4.3
CVSS Score
Published: October 16, 2023 at 07:06 PM UTC
Updated: June 17, 2026 at 06:28 AM UTC
1 product affected across 1 vendorCalendar

Using security-advisories by nextcloud?

Get instant alerts when new vulnerabilities affect security-advisories - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM4.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

Description

Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition checks the server was trying to validate strings of any length as email addresses even when megabytes of data were provided, eventually making the server busy and unresponsive. It is recommended that the Nextcloud Calendar app is upgraded to 4.4.4. The only workaround for users unable to upgrade is to disable the calendar app.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
1.0 ≤ v < 4.4.41.0.0
Affected range stops below 4.4.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-400CWE-354

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card