CVE-2026-42249

Name of the Vulnerable Software and Affected Versions Ollama for Windows versions 0.12.10 through 0.17.5

Description The update mechanism in Ollama for Windows allows Remote Code Execution due to improper handling of attacker-controlled HTTP response headers. The application constructs local file paths using values from these headers without validation, passing them to the filepath.Join() function. This enables path traversal using sequences like ../ to write files outside the intended update staging directory. An attacker capable of influencing update responses can write arbitrary executables to locations accessible to the current user, such as the Windows Startup directory. When combined with a lack of signature verification for updates, malicious payloads can be delivered, written to sensitive locations, and executed automatically and persistently without user interaction, as the software performs silent automatic updates.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.