What is CVE-2026-34820?

CVE-2026-34820 is a medium-severity vulnerability in Endian Firewall, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-04-02.

How severe is CVE-2026-34820?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Endian Firewall

CVE-2026-34820

Endian Firewall version 3.3.25 and prior allow stored cross-site scripting (XSS) via the remark parameter to /manage/ipsec/. An authenticated attacker can inject arbitrary JavaScript that is stored and executed when other users view the af…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (10.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

Affected products

Endian Firewall — versions 3.3.25

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Endian Release Notes (release-notes)
VulnCheck Advisory: Endian Firewall /manage/ipsec/ remark Stored Cross-Site Scripting (third-party-advisory)

Frequently asked questions

What is CVE-2026-34820?: CVE-2026-34820 is a medium-severity vulnerability in Endian Firewall, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-04-02.
How severe is CVE-2026-34820?: Medium severity. CVSS v3 base score is 6.4 out of 10.