CVE-2026-44612 Overview
CVE-2026-44612 is an insecure library loading vulnerability in the Bytello Share (Windows Edition) installer executable. The installer loads Dynamic Link Libraries (DLLs) from its working directory without validating their origin or integrity. An attacker who places a crafted DLL in the same directory as the installer can trigger arbitrary code execution. The executed code runs with the privileges of the user invoking the installer. The flaw is categorized under [CWE-427] Uncontrolled Search Path Element.
Critical Impact
Successful exploitation results in arbitrary code execution on the affected Windows host with the privileges of the user who launches the Bytello Share installer.
Affected Products
- Bytello Share (Windows Edition) installer executable
- Distributions obtained from the Bytello download portal
- Windows endpoints where the installer is executed from a writable directory
Discovery Timeline
- 2026-05-13 - CVE-2026-44612 published to NVD
- 2026-05-13 - Last updated in NVD database
Technical Details for CVE-2026-44612
Vulnerability Analysis
The Bytello Share installer for Windows resolves DLL dependencies using an unsafe search order. When the installer starts, Windows attempts to load required libraries from the application's current working directory before checking trusted system locations. This behavior allows a malicious DLL placed alongside the installer to be loaded instead of a legitimate library. Once loaded, the attacker-controlled DLL executes within the installer process and inherits the invoking user's privileges. If a privileged user runs the installer, the impact extends to administrator-level code execution on the host.
Root Cause
The root cause is an uncontrolled search path element as defined in [CWE-427]. The installer does not specify fully qualified paths when loading dependencies and does not use SetDefaultDllDirectories or LoadLibraryEx with safe search flags. Windows therefore falls back to the legacy DLL search order, which includes the application directory and the current working directory before System32. Any DLL filename that matches an expected dependency will be loaded without signature or path verification.
Attack Vector
Exploitation requires local access and user interaction. An attacker stages a malicious DLL in a directory that also contains the Bytello Share installer, such as a shared download folder, a removable drive, a network share, or an archive extracted by the user. When the user launches the installer from that directory, Windows loads the planted DLL. The technique aligns with common DLL search order hijacking and DLL side-loading patterns. The vulnerability does not require network access or authentication credentials.
The vulnerability mechanism is described in the JVN Security Advisory. No verified proof-of-concept code has been released.
Detection Methods for CVE-2026-44612
Indicators of Compromise
- Presence of unsigned or unexpected DLL files in directories containing the Bytello Share installer executable
- Bytello Share installer process loading DLLs from user-writable locations such as Downloads, Desktop, or removable media
- Child processes spawned by the installer that do not match the expected installation workflow
- Outbound network connections initiated by the installer process to non-Bytello infrastructure
Detection Strategies
- Monitor process image load events (Sysmon Event ID 7) for the Bytello Share installer to identify DLLs loaded from non-standard paths
- Alert on installer executables launched from user-writable directories that load unsigned modules
- Hunt for file write events that drop DLLs into the same directory as a recently downloaded installer
Monitoring Recommendations
- Inventory all hosts where the Bytello Share installer has been executed using endpoint telemetry
- Track download folders and shared network paths for co-located installer and DLL pairs
- Enable Windows Defender Application Control or AppLocker logging to record unsigned DLL load attempts
How to Mitigate CVE-2026-44612
Immediate Actions Required
- Verify the source of the Bytello Share installer and download it only from the official Bytello Download Help page
- Move the installer to a clean, dedicated directory that contains no other files before executing it
- Restrict execution of the installer to administrators using application control policies until a patched build is confirmed
Patch Information
No vendor patch has been referenced in the NVD entry at the time of publication. Refer to the JVN Security Advisory and the Bytello vendor site for updates and a fixed installer build.
Workarounds
- Execute the installer from an empty directory to prevent adjacent DLLs from being loaded
- Block execution of the installer from user-writable locations such as Downloads and removable drives via AppLocker or Windows Defender Application Control
- Enforce SmartScreen and code signature verification on downloaded executables
- Educate users to avoid running installers extracted alongside other files from untrusted archives
# Configuration example
# AppLocker rule fragment denying execution of unsigned DLLs from user paths
# Deny: %OSDRIVE%\Users\*\Downloads\*.dll
# Deny: %OSDRIVE%\Users\*\Desktop\*.dll
# Allow only signed publisher: O=Bytello, signed installers from a controlled path
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
