ZDI-26-403: (0Day) Ollama downloadBlob Improper Validation of Array Index Denial-of-Service Vulnerability
A denial-of-service vulnerability exists in the Ollama product due to improper validation of array indices in the downloadBlob function. This flaw allows remote attackers to cause a denial-of-service condition without requiring authentication. The vulnerability arises from accessing memory beyond the allocated array bounds. No patch or official fix information is currently available. Mitigation is limited to restricting interaction with the affected product.
AI Analysis
Technical Summary
The Ollama product contains a vulnerability in its downloadBlob function where user-supplied data is not properly validated, leading to out-of-bounds memory access. This can be exploited remotely without authentication to cause a denial-of-service (DoS) condition. The vulnerability has been assigned a CVSS score of 7.5 by the Zero Day Initiative, indicating a high impact on availability but no impact on confidentiality or integrity. The advisory does not provide details on affected versions or available patches. The only recommended mitigation is to restrict access to the product until a fix is available.
Potential Impact
Remote attackers can cause a denial-of-service condition on affected Ollama installations by exploiting improper validation of array indices in the downloadBlob function. This results in memory access beyond allocated bounds, leading to system instability or crash. There is no impact on confidentiality or integrity, and no authentication is required to exploit this vulnerability.
Mitigation Recommendations
No official patch or fix has been disclosed. The vendor has not provided remediation guidance. The only practical mitigation is to restrict interaction with the Ollama product to trusted users or networks to reduce exposure until a fix is available. Monitor the vendor advisory for updates on patch availability.
ZDI-26-403: (0Day) Ollama downloadBlob Improper Validation of Array Index Denial-of-Service Vulnerability
Description
A denial-of-service vulnerability exists in the Ollama product due to improper validation of array indices in the downloadBlob function. This flaw allows remote attackers to cause a denial-of-service condition without requiring authentication. The vulnerability arises from accessing memory beyond the allocated array bounds. No patch or official fix information is currently available. Mitigation is limited to restricting interaction with the affected product.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Ollama product contains a vulnerability in its downloadBlob function where user-supplied data is not properly validated, leading to out-of-bounds memory access. This can be exploited remotely without authentication to cause a denial-of-service (DoS) condition. The vulnerability has been assigned a CVSS score of 7.5 by the Zero Day Initiative, indicating a high impact on availability but no impact on confidentiality or integrity. The advisory does not provide details on affected versions or available patches. The only recommended mitigation is to restrict access to the product until a fix is available.
Potential Impact
Remote attackers can cause a denial-of-service condition on affected Ollama installations by exploiting improper validation of array indices in the downloadBlob function. This results in memory access beyond allocated bounds, leading to system instability or crash. There is no impact on confidentiality or integrity, and no authentication is required to exploit this vulnerability.
Mitigation Recommendations
No official patch or fix has been disclosed. The vendor has not provided remediation guidance. The only practical mitigation is to restrict interaction with the Ollama product to trusted users or networks to reduce exposure until a fix is available. Monitor the vendor advisory for updates on patch availability.
Technical Details
- Article Source
- {"url":"http://www.zerodayinitiative.com/advisories/ZDI-26-403/","fetched":true,"fetchedAt":"2026-07-09T11:08:24.823Z","wordCount":234}
Threat ID: 6a4f818768715ace4335a9ad
Added to database: 07/09/2026, 11:09:59 UTC
Last enriched: 07/09/2026, 11:10:09 UTC
Last updated: 07/09/2026, 20:08:59 UTC
Views: 11
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