# 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.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jul 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-c7vp-gjfc-x6p8, MINI-5j47-hfq5-gjmx

## 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 (Improper Validation of Array Index)

## Which versions are affected by CVE-2026-15685?

It affects 1 product.


Products: Ollama Ollama.

## How do I fix CVE-2026-15685?

Apply the vendor's patch.

## 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](https://insights.sbomify.com/CVE-2025-63389/): Ollama Platform has missing authentication enabling attackers to perform model management operations (critical 9.8)
- [CVE-2024-45436](https://insights.sbomify.com/CVE-2024-45436/): Ollama can extract members of a ZIP archive outside of the parent directory (critical 9.1)
- [CVE-2026-7482](https://insights.sbomify.com/CVE-2026-7482/): Ollama heap out-of-bounds read in GGUF tensor parsing leaks server process memory to unauthenticated remote attackers (high 8.8)
- [CVE-2024-37032](https://insights.sbomify.com/CVE-2024-37032/): Ollama does not validate the format of the digest (sha256 with 64 hex digits) (high 8.8)
- [CVE-2025-15514](https://insights.sbomify.com/CVE-2025-15514/): Ollama Multi-Modal Model Image Processing NULL Pointer Dereference (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15685 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-15685 in the wild and no public exploit code.

Affected product: Ollama. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15685/ (Markdown: https://insights.sbomify.com/CVE-2026-15685/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15685
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15685
- OSV: https://osv.dev/vulnerability/CVE-2026-15685

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15685/
Summaries are generated and may contain mistakes; the official description above is the record.