Ollama up to 0.17.5 on Windows Digital Signature code download

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Ollama up to 0.17.5 on Windows. This affects an unknown function of the component Digital Signature Handler. The manipulation leads to code download. This vulnerability is uniquely identified as CVE-2026-42248. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Ollama up to 0.17.5 on Windows. This issue affects an unknown functionality of the component Digital Signature Handler. The manipulation with an unknown input leads to a code download vulnerability. Using CWE to declare the problem leads to CWE-494. The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code. Impacted is integrity. The summary by CVE is:

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.

The weakness was disclosed by Bartłomiej Dmitruk. The advisory is shared at cert.pl. The identification of this vulnerability is CVE-2026-42248 since 04/25/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1495 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-26210). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Ollama

Version

• 0.17.0
• 0.17.1
• 0.17.2
• 0.17.3
• 0.17.4
• 0.17.5

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion