External risk intelligence

Rotaban Unrestricted File Upload Vulnerability

CVE advisorySeverity: CRITICAL (CVSS 9.9)

CVE-2026-11839

A critical vulnerability in Rotaban allows uploading dangerous files to a web server, potentially enabling system control. This affects Rotaban versions before V2026.06.003 and requires authenticated, low-privilege access. The impact depends on the application's deployment and network exposure, necessitating verificati

4Halo Surface Signal

Unrestricted File Upload

External exposure likelihood

Halo Surface Signal score for CVE-2026-11839

The vulnerability allows the upload of a web shell to a web server within the Rotaban application. As a web server application, it is commonly deployed to host web services or interfaces that are typically accessible via the internet or a corporate network, making the exploitation of file upload functions a likely scenario for an internet-facing service.

PCI scan relevance

PCI Relevance for CVE-2026-11839

Yes

CVE-2026-11839 — Halo PCI Relevance: Yes. Under typical PCI ASV external scan criteria, this issue may be flagged for scan prioritization.

This vulnerability allows unrestricted file uploads of web shells, which can lead to a system takeover and is a class of vulnerability that typically causes an automatic PCI ASV scan failure.

Scan-prioritization guidance only—not a PCI DSS certification or ASV attestation.

CVSS vector

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

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability has been identified in Rotaban software that could allow an attacker to upload harmful files to a web server, potentially enabling them to take control of the system. The primary concern is to confirm if our organization uses the affected technology and assess any potential exposure.

  • Harmful files can be uploaded to servers.
  • Confirms usage and potential exposure.
  • Verify Rotaban use and assess risk.

Attack Path

How an attacker could exploit the issue

An attacker with low-privilege access to the Rotaban application could upload a web shell. This could then lead to the attacker gaining administrative control over the web server, potentially impacting confidentiality, integrity, and availability.

  • Requires authenticated, low-privilege access.
  • Uploading a file with a dangerous type.
  • Full control over the web server.

Live Threat

Current exploitation, exposure, and threat context

A critical vulnerability in Rotaban could allow an authenticated user to upload a web shell to the web server. This could enable an attacker to execute arbitrary code on the server, potentially compromising its integrity and confidentiality. The impact is contingent on the application's deployment and network exposure.

  • Web server compromised.
  • Unrestricted file upload.
  • Server code execution.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

The Basharsoft Rotaban application is susceptible to unrestricted file uploads, potentially allowing attackers to deploy web shells. This vulnerability resides within the application itself, indicating that application owners and the platform team responsible for Rotaban are the primary stakeholders. The initial action should be to pinpoint all Rotaban deployments, verify their accessibility and business criticality, and identify the accountable application owner to formulate a targeted remediation strategy.

  • Application owners and platform teams own this issue.
  • Verify Rotaban's accessibility and business criticality.
  • Plan remediation based on identified risk.

Frequently asked questions

What is Rotaban software?

Rotaban is an application developed by Başarsoft Information Technologies Inc. It functions as a web server application, commonly used to host web services or interfaces that support organizational business processes and data management.

What does CWE-434 mean for CVE-2026-11839?

CWE-434 refers to an Unrestricted Upload of File with Dangerous Type. In the context of CVE-2026-11839, this means the software does not sufficiently check the file types being uploaded. An attacker can exploit this by uploading a web shell, which is a script that allows them to run malicious commands and gain control over the web server.

How can an attacker trigger this vulnerability?

An attacker needs low-privilege authenticated access to the Rotaban application to trigger this flaw. The vulnerability involves the system improperly accepting malicious files. Simply visiting the site without an account or having access that lacks file upload permissions will not trigger the bug.

Is my Rotaban instance at risk?

According to Halo Surface Signal, Rotaban is typically deployed as an internet-facing or network-accessible service. If your instance is reachable over the internet, it is more likely to be targeted. You should check if you are running version V2026.06.002 or earlier, as these are the versions confirmed to be affected by this issue.

What should I do if I use Rotaban?

First, identify all instances of Rotaban within your environment and confirm which versions are running. Determine if these servers are accessible from the internet or other untrusted networks. Coordinate with your application owners to prioritize these systems and prepare to apply updates to version V2026.06.003 or newer once available from the vendor.

References

Sources and related resources

Primary sources: NVD, CVE.org.

NVDPublished