XSS in Nextcloud Server

CVE-2021-22878

Nextcloud Server prior to 20.0.6 is vulnerable to reflected cross-site scripting (XSS) due to lack of sanitization in `OC.Notification.show`.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.011 (61.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-22878?
CVE-2021-22878 is a medium-severity vulnerability in Nextcloud Server, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2021-03-03.
How severe is CVE-2021-22878?
Medium severity. CVSS v3 base score is 4.8 out of 10.