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Vulnerability record · CVE-2021-20729 · published 31 March 2022

CVE-2021-20729: Netgate pfsense plus cross-site scripting vulnerability

Netgate · Pfsense Plus

Cross-site scripting vulnerability in pfSense CE and pfSense Plus (pfSense CE software versions 2.5.2 and earlier, and pfSense Plus software versions 21.05 and earlier) allows a remote attacker to inject an arbitrary script via a malicious URL.

6.1 CVSS 3.1 Medium EPSS 2.9% · top 13.7% CWE-79 · Cross-site scripting
6.1CVSS 3.1 base score, v2 4.3
2.9%EPSS exploitation probability, 30 days
NoNot in CISA KEV
2Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

Description

Cross-site scripting vulnerability in pfSense CE and pfSense Plus (pfSense CE software versions 2.5.2 and earlier, and pfSense Plus software versions 21.05 and earlier) allows a remote attacker to inject an arbitrary script via a malicious URL.

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

Affected products

2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://docs.netgate.com/downloads/pfSense-SA-21_02.captiveportal.asc Third Party Advisory
https://jvn.jp/en/jp/JVN87751554/index.html Third Party AdvisoryVDB Entry
https://docs.netgate.com/downloads/pfSense-SA-21_02.captiveportal.asc Third Party Advisory
https://jvn.jp/en/jp/JVN87751554/index.html Third Party AdvisoryVDB Entry

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2021-20729), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.