7.7
HIGH CVSS 4.0
CVE-2026-42248
Missing Signature Verification for Updates in Ollama
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.

INFO

Published Date :

April 29, 2026, 12:16 p.m.

Last Modified :

April 29, 2026, 12:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-42248 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 HIGH 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
CVSS 4.0 HIGH [email protected]
Solution
Update Ollama for Windows to a version that validates downloaded executables.
  • Ensure Ollama for Windows performs signature validation.
  • Update Ollama for Windows to the latest version.
  • Verify update executables are trusted.
  • Disable automatic updates if necessary.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-42248.

URL Resource
https://cert.pl/en/posts/2026/04/CVE-2026-42248/
https://ollama.com/
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-42248 is associated with the following CWEs:

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-42248 vulnerability anywhere in the article.

  • cert.pl
Vulnerabilities in Ollama software

Vulnerabilities in Ollama software CVE ID CVE-2026-42248 Publication date 29 April 2026 Vendor Ollama Product Ollama Vulnerable versions From 0.12.10 through 0.17.5 Vulnerability type (CWE) Download o ... Read more

Published Date: Apr 29, 2026 (2 hours, 19 minutes ago)

The following table lists the changes that have been made to the CVE-2026-42248 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Apr. 29, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:A/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-494
    Added Reference https://cert.pl/en/posts/2026/04/CVE-2026-42248/
    Added Reference https://ollama.com/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.