CVE-2026-15685: ollama (CVSS 7.5)

Description

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.

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CVSS v3.1 Score

7.5

HIGH

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0039

Probability of exploitation

0.32%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-129 CWE-129

Affected Products

Vendor	Product	Versions
ollama	ollama	All

References

Other References

https://www.zerodayinitiative.com/advisories/ZDI-26-403/

Frequently Asked Questions

What is CVE-2026-15685? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2026-15685? +

CVE-2026-15685 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0039, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-15685? +

CVE-2026-15685 affects products from ollama, specifically: ollama. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-15685? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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