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 affected page.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.002 (13.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 13th percentile — 13.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001
Affected products
- Endian Firewall — versions 3.3.25
- Endian Firewall Community
Weakness classification (CWE)
References
- help.endian.com/hc/en-us/sections/360004371358-Community (release-notes, Release Notes)
- www.vulncheck.com/advisories/endian-firewall-manage-ipsec-remark-stored-cross-s… (Third Party Advisory, 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.