Vulnerability in Froxlor
CVE-2026-100717
froxlor is a server administration panel. In versions 2.3.10 and earlier, Validate::validateUrl rejects carriage return and line feed characters only in the path, query and fragment components returned by parse_url, and never inspects the userinfo (user:pass@) components. This is an incomplete fix for GHSA-c3p2. An authenticated low-privilege customer with subdomain-create rights (no admin or change_serversettings privilege required) can supply a subdomain redirect URL that carries a CR/LF payload in the userinfo portion (e.g. http://user%0areturn 200 "pwned";%0a@evil.com/). The value passes validation, survives IDNA encoding, and is written verbatim into the generated nginx or Apache vhost configuration, allowing the attacker to break out of the emitted directive and inject arbitrary web-server configuration lines. froxlor regenerates and reloads the web-server configuration as root, so the injected directives take effect server-wide and can hijack responses or read local files. The issue is fixed in version 2.3.12.
Vulnerability class: CRLF Injection
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/froxlor/froxlor/security/advisories/GHSA-gxx3-hwjc-h2gp (vendor-advisory)
- www.vulncheck.com/advisories/froxlor-before-2.3.12-crlf-injection-via-validateu… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100717?
- CVE-2026-100717 is a critical-severity vulnerability in Froxlor, classified under CRLF Injection. CVSS score: 9.9/10. Published 2026-09-26.
- How severe is CVE-2026-100717?
- Critical severity. CVSS v3 base score is 9.9 out of 10.