Improper Input ValidationWeakness · CWE-20

CVE-2026-45556

CRITICAL · 9.9 CVSS v3.1 Published 2026-06-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Roxy-WI is a web interface for managing Haproxy, Nginx, Apache and Keepalived servers. In versions 8.2.6.4 and prior, POST /waf/<service>/<server_ip>/rule/<rule_id>/save accepts a config_file_name form field that is passed straight through to config_mod.master_slave_upload_and_restart(...) as the destination path. The validation chain (_replace_config_path_to_correct → check_is_conf) only requires the path to contain a hard-coded service substring (nginx/haproxy/apache2/httpd/keepalived) and the substring conf or cfg, and to not contain ... The encoded-slash substitution 92 → / is applied before the substring check, so the attacker can build any absolute path anywhere on the LB filesystem as long as it satisfies those substring constraints. The body of the WAF rule (config form field) is written verbatim to that path. By choosing a filename like 92etc92cron.d92nginx_cfg_evil (resolving to /etc/cron.d/nginx_cfg_evil), an attacker drops a cron entry on the load balancer with attacker-controlled content. Cron parses the file on its next scan, executing the embedded job as root — full RCE on every load balancer the caller's group manages. At time of publication, there are no publicly available patches.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Roxy-WI versions 8.2.6.4 and prior have a path traversal vulnerability in POST /waf/<service>/<server_ip>/rule/<rule_id>/save where the config_file_name form field is passed directly to file write operations without proper sanitization. The validation only checks for hardcoded service substrings (nginx/haproxy/apache2/httpd/keepalived) and conf/cfg, and substitutes 92 → / before validation, allowing attackers to write arbitrary files (e.g., /etc/cron.d/nginx_cfg_evil) for root RCE via cron execution.

MitigationSince no patch exists, immediately disable the WAF rule save functionality or place Roxy-WI behind a WAF/API gateway with strict input validation blocking path traversal patterns (92, /, ..). Consider network segmentation to limit exposure and monitor for exploitation attempts.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Roxy-WI installation and version
    Locate the Roxy-WI installation directory and check for version information in version files, login page source, or configuration files. Common locations include /opt/roxy-wi, /usr/share/roxy-wi, or the application's main directory.
    Affected if The installed version is 8.2.6.4 or any version prior to 8.2.6.4
  2. Verify WAF module is enabled
    Check if the WAF functionality is enabled in Roxy-WI configuration. Look for WAF-related settings in the main config file (typically roxy-wi.conf or similar) and confirm the /waf routes are active.
    Affected if The WAF module is enabled and the vulnerable endpoint /waf/<service>/<server_ip>/rule/<rule_id>/save is accessible
  3. Confirm the service uses vulnerable config_file_name parameter
    Inspect the web application firewall save endpoint by reviewing the application code at the route handling /waf/*/rule/*/save. Look for the config_file_name form parameter handling and verify the substitution of 92 to / character.
    Affected if The application processes config_file_name without proper path sanitization and performs the 92 → / substitution before validation
  4. Check for unauthorized file modifications
    Review /etc/cron.d, /etc/cron.daily, and other cron directories for newly created or modified files with nginx, haproxy, apache, or roxy-related names. Also check /tmp and /var/tmp for unexpected scripts.
    Affected if Any suspicious cron jobs or scripts exist that were not created by legitimate administrators, particularly those containing encoded paths (92 sequences) or referencing Roxy-WI services
  5. Analyze web access logs for exploitation attempts
    Search web server access logs (nginx, apache, haproxy) for POST requests to /waf/*/rule/*/save endpoints containing path traversal patterns in the config_file_name parameter. Look for sequences like .., /, or encoded path separators.
    Affected if Logs show POST requests to the vulnerable endpoint with suspicious config_file_name values containing path traversal sequences

A user is affected if they run Roxy-WI version 8.2.6.4 or prior with the WAF module enabled and the vulnerable endpoint accessible, allowing arbitrary file writes that could result in root-level code execution.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Since no patch exists, immediately disable the WAF rule save functionality or place Roxy-WI behind a WAF/API gateway with strict input validation blocking path traversal patterns (92, /, ..). Consider network segmentation to limit exposure and monitor for exploitation attempts.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
36.0 hours of engineering $6,400
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $10,240.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-45556 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-45556 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data