CVE-2026-42248 HIGH

CVE-2026-42248: Missing Signature Verification for Updates in Ollama

Vendor Ollama
Product Ollama
Weakness CWE-494 · Download without integrity check
Published April 29, 2026
Last update April 29, 2026

CVSS base score

7.7/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L

What the vulnerability does

01Description

Ollama for Windows does not perform integrity or authenticity verification of downloaded update executables. Unlike other platforms, the Windows implementation of the update verification routine unconditionally returns success so no digital signature or trust validation is performed before staging or executing update payloads, enabling attacker‑supplied executables to be accepted and later executed by the application. Critically, Ollama for Windows performs silent automatic updates, so the malicious payload may be installed automatically without user awareness. Maintainers of this project were notified early about this vulnerability, but didn't respond with the details of vulnerability or vulnerable version range. Versions from 0.12.10 to 0.17.5 were tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.

Key dates

02Disclosure timeline

April 29, 2026 CVE published
April 29, 2026 Record updated