Ollama’s downloadBlob function fails to validate the size of user‑supplied data, allowing an attacker to cause a memory access past the end of an allocated array. This failure represents CWE‑129 (Improper Validation of Array Index) and CWE‑787 (Out‑of‑Bounds Write), and results in a crash or restart of the service, creating a denial‑of‑service condition. The vulnerability does not alter confidentiality or integrity, but it can be invoked remotely without authentication.

All installations of Ollama are potentially affected. No specific version range is listed; any installation that has not applied a vendor fix is at risk.

The CVSS score of 7.5 indicates a high severity impact, while the EPSS score is < 1% and the vulnerability is not listed in the CISA KEV catalog. The high severity score indicates that a successful exploit would disrupt the service. Based on the description, it is inferred that an attacker can trigger a denial‑of‑service condition remotely without authentication. However, the advisory does not state whether the downloadBlob endpoint is publicly reachable or limited to internal traffic, so the exact exposure level is unknown.