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

> Ollama for Windows fails to verify update signatures, allowing attackers to execute malicious code via silent automatic updates.

- **Severity:** High 7.7 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Apr 2026
- **Updated:** 29 Apr 2026
- **Also known as:** GHSA-5fjh-wjgp-25ph, MINI-3vrv-h2w3-83mv

## What is CVE-2026-42248?

CVE-2026-42248 is a high-severity vulnerability in Ollama, published on 29 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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.

Weakness: CWE-494 (Download of Code Without Integrity Check)

## Which versions are affected by CVE-2026-42248?

It affects 1 product.


Products: Ollama Ollama.

## How do I fix CVE-2026-42248?

No fix published yet.

## Is CVE-2026-42248 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42248 exists.

Public exploit code:

- Ollama Windows Auto-Update Path Traversal Persistence (metasploit)

## Other vulnerabilities in Ollama

- [CVE-2025-63389](https://insights.sbomify.com/CVE-2025-63389/): Ollama Platform has missing authentication enabling attackers to perform model management operations (critical 9.8)
- [CVE-2024-45436](https://insights.sbomify.com/CVE-2024-45436/): Ollama can extract members of a ZIP archive outside of the parent directory (critical 9.1)
- [CVE-2026-7482](https://insights.sbomify.com/CVE-2026-7482/): Ollama heap out-of-bounds read in GGUF tensor parsing leaks server process memory to unauthenticated remote attackers (high 8.8)
- [CVE-2024-37032](https://insights.sbomify.com/CVE-2024-37032/): Ollama does not validate the format of the digest (sha256 with 64 hex digits) (high 8.8)
- [CVE-2025-15514](https://insights.sbomify.com/CVE-2025-15514/): Ollama Multi-Modal Model Image Processing NULL Pointer Dereference (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42248 and fix it if it is affected.

What it is: CVE-2026-42248 is a high-severity vulnerability in Ollama, published on 29 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42248 exists.

Affected product: Ollama. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-42248/ (Markdown: https://insights.sbomify.com/CVE-2026-42248/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42248
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42248
- OSV: https://osv.dev/vulnerability/CVE-2026-42248

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42248/
Summaries are generated and may contain mistakes; the official description above is the record.