CVE-2026-15685 Ollama downloadBlob Improper Validation of Array Index Denial-of-Service Vulnerability
Remote attackers can cause a denial-of-service condition in Ollama by exploiting an improper array index validation flaw in the downloadBlob function.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-15685?
CVE-2026-15685 is a high-severity denial of service vulnerability in Ollama, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-129
Which versions are affected by CVE-2026-15685?
It affects 1 product.
Products include Ollama Ollama.
How do I fix CVE-2026-15685?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-15685 being exploited?
There is no known exploitation of CVE-2026-15685 in the wild and no public exploit code.
Other vulnerabilities in Ollama
- CVE-2025-63389 Ollama Platform has missing authentication enabling attackers to perform model management operations
- CVE-2024-45436 Ollama can extract members of a ZIP archive outside of the parent directory
- CVE-2026-7482 Ollama heap out-of-bounds read in GGUF tensor parsing leaks server process memory to unauthenticated remote attackers
- CVE-2024-37032 Ollama does not validate the format of the digest (sha256 with 64 hex digits)
- CVE-2025-15514 Ollama Multi-Modal Model Image Processing NULL Pointer Dereference
Sources
Also known as GHSA-c7vp-gjfc-x6p8, MINI-5j47-hfq5-gjmx.