# CVE-2025-1975: Ollama Server DoS via improper array index validation in /api/pull

Source: https://junglewise.ai/threats/cve-2025-1975-ollama-server-dos-via-improper-array-index-validation-in-api-pull  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-05-16. Updated: 2026-06-06  
License: CC BY 4.0 with a link back

CVE-2025-1975 · Severity: high · CVSS 7.5 · Published 2025-05-16

Ollama, a popular tool for running large language models locally, is vulnerable to a flaw that allows an attacker to crash the server. By sending a specially crafted request to the model download interface, a remote user can trigger a system failure, leading to a complete service outage. This prevents legitimate users and applications from accessing AI models until the service is manually restarted.

Technologies: [github.com/ollama/ollama (Go)](https://junglewise.ai/threats/technologies/github-com-ollama-ollama), [Ollama](https://junglewise.ai/threats/technologies/ollama), [ollama (PyPI)](https://junglewise.ai/threats/technologies/pypi-ollama). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Ollama](https://junglewise.ai/threats/vendors/ollama), [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2025-1975 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-1975 being exploited in the wild.

**How severe is CVE-2025-1975?** High severity, with a CVSS score of 7.5, published 16 May 2025.

**Which products and versions are affected?** github.com/ollama/ollama (Go) <= 0.5.11, SEMVER:introduced=0, SEMVER:introduced=0,last_affected=0.5.11; Ollama <= 0.5.11; ollama (PyPI) ECOSYSTEM:introduced=0,last_affected=0.5.11.

**Is there a fix for CVE-2025-1975?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2025-1975 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2025-1975?** Check whether you run github.com/ollama/ollama (Go), Ollama or ollama (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A Denial of Service (DoS) vulnerability exists in Ollama Server version 0.5.11 and earlier due to an improper validation of array index access (CWE-129). The flaw is located within the /api/pull endpoint, which is used for downloading models. An attacker can exploit this by providing a malicious manifest file with customized content that triggers an out-of-bounds array access during the pull process. This results in a server crash. The attack can be executed remotely over the network without authentication or user interaction. As of the advisory date, no patched version has been identified.

## Affected products

- Ollama Ollama <= 0.5.11

## Identifiers

- CVE-2025-1975
- GHSA-wrh5-cmwx-q2qr
- GO-2025-3695
- PYSEC-2025-145

## Timeline

- 2025-05-16: advisory: GitHub Advisory GHSA-wrh5-cmwx-q2qr published
- 2025-05-16: disclosed: CVE-2025-1975 assigned

## References

- [https://huntr.com/bounties/921ba5d4-f1d0-4c66-9764-4f72dffe7acd](https://huntr.com/bounties/921ba5d4-f1d0-4c66-9764-4f72dffe7acd)
- [https://pkg.go.dev/vuln/GO-2025-3695](https://pkg.go.dev/vuln/GO-2025-3695)
- [https://github.com/pypa/advisory-database/tree/main/vulns/ollama/PYSEC-2025-145.yaml](https://github.com/pypa/advisory-database/tree/main/vulns/ollama/PYSEC-2025-145.yaml)

## Related threats

- [Ollama server-side request forgery in Pull API](https://junglewise.ai/threats/cve-2026-108836-a-vulnerability-has-been-found-in-ollama-up-to-0-34-1-the)
- [Ollama authorization bypass in experimental agent Bash tool approval](https://junglewise.ai/threats/cve-2026-102697-ollama-versions-0-14-0-before-0-31-2-contain-an-incorrect)
- [Ollama integer overflow in GGUF decoder](https://junglewise.ai/threats/cve-2026-86289-ollama-integer-overflow-in-gguf-decoder)
- [Ollama unvalidated redirect in model blob downloads](https://junglewise.ai/threats/cve-2026-85180-ollama-unvalidated-redirect-in-model-blob-downloads)
- [Ollama uncontrolled memory allocation in GGUF metadata parser](https://junglewise.ai/threats/cve-2026-65315-ollama-uncontrolled-memory-allocation-in-gguf-metadata-parser)