Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-13T21:30:09 Ollama: Ollama: Denial of Service via improper array index validation in downloadBlob function 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-787

Ollama downloadBlob Improper Validation of Array Index Denial-of-Service Vulnerability. This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Ollama. Authentication is not required to exploit this vulnerability. The specific flaw exists within the downloadBlob function. The issue results from the lack of proper validation of user-supplied data, which can result in a memory access past the end of an allocated array. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-27277.

A flaw was found in Ollama. This vulnerability allows remote attackers to create a denial-of-service (DoS) condition on affected installations. The issue occurs within the `downloadBlob` function due to improper validation of user-supplied data, which can lead to memory access beyond the bounds of an allocated array. An attacker can exploit this without authentication to disrupt the system's availability.

This Important vulnerability in Ollama allows a remote, unauthenticated attacker to trigger a denial-of-service condition. The flaw in the `downloadBlob` function, due to improper array index validation, can lead to memory access issues, disrupting the availability of the Ollama service when deployed in a Red Hat environment. Migration Toolkit for Applications 8 Not affected mta/mta-solution-server-rhel9 Red Hat Ansible Automation Platform 2 Not affected ansible-automation-platform-24/lightspeed-rhel8 Red Hat Ansible Automation Platform 2 Not affected ansible-automation-platform-25/lightspeed-rhel8 Red Hat OpenShift AI (RHOAI) Not affected rhoai/odh-trustyai-garak-lls-provider-dsp-rhel9 https://www.cve.org/CVERecord?id=CVE-2026-15685 https://nvd.nist.gov/vuln/detail/CVE-2026-15685 https://www.zerodayinitiative.com/advisories/ZDI-26-403/