Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-39221

20
FAUCET Score

CVE-2021-39221 describes a stored Cross-Site Scripting (XSS) vulnerability in the Nextcloud Contacts application prior to version 4.0.3. An authenticated user could exploit this by right-clicking and opening a malicious file in a new tab. The vulnerability has a CVSS score of 5.4 (Medium), indicating a network-based attack requiring low privileges and user interaction, with potential for low confidentiality and integrity impact. Despite the vulnerability, Nextcloud's strict Content-Security-Policy significantly mitigates exploitation on modern browsers. There is no evidence of active exploitation, public exploit code, or significant community discussion, and it is not listed in CISA's KEV catalog.

Impacted Technologies

VendorProductVersion(s)CPE
< 4.0.3CPE matchmatch criteria
cpe:2.3:a:nextcloud:contacts:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

6.4MEDIUM

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

Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
Exploitability Score
1.2
Impact Score
5.2
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.50%
Probability of exploitation in next 30 days
EPSS Percentile
40.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0050 is in the 62nd percentile among its peer group of 15,225 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.1 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

github.com / nextcloud/contacts/pull/2407
Third Party Advisory
github.com / nextcloud/security-advisories/security/advisories/GHSA-j6cx-mxqf-f9vc
Third Party Advisory