Auth bypass in Nextcloud Server

CVE-2021-32726

Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.13, 20.011, and 21.0.3, webauthn tokens were not deleted after a user has been deleted. If a victim reused an earlier used username, the previous user could gain access to their account. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.

EPSS: 0.018 (76.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-32726?
CVE-2021-32726 is a high-severity vulnerability in Nextcloud Server, classified under CWE-708. CVSS score: 7.1/10. Published 2021-07-12.
How severe is CVE-2021-32726?
High severity. CVSS v3 base score is 7.1 out of 10.
Is CVE-2021-32726 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.