CVE-2022-24838

Name: CVE-2022-24838
Creator: NVD / NIST
Published: 2022-04-11T21:15:08.76+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 31.55%

Last modified Jun 17, 2026

CVE-2022-24838 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Nextcloud Calendar is a calendar application for the nextcloud framework. SMTP Command Injection in Appointment Emails via Newlines: as newlines and special characters are not sanitized in the email value in the JSON request, a malicious attacker can inject newlines to break out of the `RCPT TO:<BOOKING USER'S EMAIL> ` SMTP command and begin injecting arbitrary SMTP commands. EPSS estimates a 31.55% chance of exploitation in the next 30 days.

Description

Nextcloud Calendar is a calendar application for the nextcloud framework. SMTP Command Injection in Appointment Emails via Newlines: as newlines and special characters are not sanitized in the email value in the JSON request, a malicious attacker can inject newlines to break out of the `RCPT TO:<BOOKING USER'S EMAIL> ` SMTP command and begin injecting arbitrary SMTP commands. It is recommended that Calendar is upgraded to 3.2.2. There are no workaround available.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

31.55%

98.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Nextcloud	Calendar	< 3.2.2

References

https://github.com/nextcloud/calendar/commit/7b70edfb8a0fcf0926f613ababcbd56c6ecd9f35Patch, Third Party Advisory
https://github.com/nextcloud/calendar/pull/4073Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8xv5-4855-24qfThird Party Advisory
https://github.com/nextcloud/calendar/commit/7b70edfb8a0fcf0926f613ababcbd56c6ecd9f35Patch, Third Party Advisory
https://github.com/nextcloud/calendar/pull/4073Patch, Third Party Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-8xv5-4855-24qfThird Party Advisory

Timeline

Published: Apr 11, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2022-24838?

How severe is CVE-2022-24838?

CVE-2022-24838 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 31.55% probability of exploitation in the next 30 days.

How do I fix CVE-2022-24838?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-24838?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST