# CVE-2026-42248: Ollama for Windows missing integrity check in update mechanism

Source: https://junglewise.ai/threats/cve-2026-42248-ollama-for-windows-missing-integrity-check-in-update-mechanism  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-29. Updated: 2026-05-18  
License: CC BY 4.0 with a link back

CVE-2026-42248 · Severity: critical · CVSS 9.8 · Published 2026-04-29

Ollama for Windows, a tool used to run large language models locally, fails to verify the authenticity of its software updates. Because the application performs these updates automatically and silently, an attacker could trick the software into downloading and running malicious code. This could lead to a complete takeover of the user's computer without any warning or interaction required from the user.

## Quick answers

**Is CVE-2026-42248 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-42248 being exploited in the wild.

**How severe is CVE-2026-42248?** Critical severity, with a CVSS score of 9.8, published 29 April 2026.

**Which products and versions are affected?** Ollama Ollama 0.12.10 through 0.17.5.

**Is there a fix for CVE-2026-42248?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-42248 attacked?** It is attacked over the network or from the adjacent network, in a network appliance.

**Am I affected by CVE-2026-42248?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

Ollama for Windows contains a vulnerability where the update verification routine (CWE-494) unconditionally returns success, bypassing digital signature and trust validation. This flaw is specific to the Windows implementation and affects the silent automatic update mechanism. An attacker capable of intercepting or spoofing the update server's response can deliver a malicious executable that the application will stage and execute without user interaction. When chained with other flaws like path traversal, this can lead to persistent remote code execution. Versions 0.12.10 through 0.17.5 are confirmed vulnerable.

## Affected products

- Ollama Ollama 0.12.10 through 0.17.5

## Timeline

- 2026-04-29: disclosed
- 2026-04-29: advisory

## References

- [https://cert.pl/en/posts/2026/04/CVE-2026-42248/](https://cert.pl/en/posts/2026/04/CVE-2026-42248/)
- [https://ollama.com/](https://ollama.com/)