XSS in Froxlor
CVE-2026-100720
Froxlor 2.0.0 through 2.3.10 is vulnerable to stored cross-site scripting. When a customer (the lowest-privileged authenticated role) uploads an SSL certificate for one of their own domains, the Certificates API add()/update() methods parse it with openssl_x509_parse() and store the issuer organization (issuer['O']) value verbatim without sanitization. Froxlor's table-listing renderer then emits scalar cells through Twig's `raw` filter, disabling HTML auto-escaping, so when an administrator or reseller opens Domains > SSL certificates the attacker-supplied issuer value executes as script in the privileged user's session. This crosses a privilege boundary from customer to admin and can result in full administrator account takeover; because a Froxlor admin controls webserver, DNS, and PHP configuration applied by a cron job running as root, the issue can be further escalated to command execution as root on the managed server. The issue is fixed in Froxlor 2.3.12.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-89vj-gqqr-73p8) (vendor-advisory)
- VulnCheck Advisory: Froxlor before 2.3.12 Stored XSS via SSL certificate issuer (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100720?
- CVE-2026-100720 is a high-severity vulnerability in Froxlor, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-09-26.
- How severe is CVE-2026-100720?
- High severity. CVSS v3 base score is 8.7 out of 10.