CVE-2026-86289: Ollama GGUF Decoder gguf.go readGGUFV1String integer overflow
A vulnerability was found in Ollama up to 0.31.1. This issue affects the function readGGUFV1String of the file fs/ggml/gguf.go of the component GGUF Decoder. Performing a manipulation results in integer overflow. The attack is possible to be carried out remotely. The exploit has been made public and could be used. Upgrading to version 0.31.2-rc1 is capable of addressing this issue. The patch is named 67b6a1c2d45321e0cb3c04a18073f9818de7724b. It is recommended to upgrade the affected component.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Ollamato a version that resolves this vulnerability.Fixed in 0.31.2-rc1Patch 67b6a1c2d45321e0cb3c04a18073f9818de7724b - Compensating control
Because the vulnerability can be exploited remotely, restrict network access to Ollama (and any ports exposing it) to only trusted clients until the upgrade to 0.31.2-rc1 is completed.
Event History
Frequently Asked Questions
Which deployments are affected?
Ollama versions up to 0.31.1 are affected. The vulnerable code is in the GGUF Decoder, specifically the readGGUFV1String function in fs/ggml/gguf.go.
What does exploitation require?
The issue can be exploited remotely through manipulation of data processed by the GGUF Decoder. No privileges are required, but user interaction is required according to the supplied severity vector.
Is public exploit information available?
Yes. The exploit has been made public and could be used.
What version addresses the issue?
Upgrading to Ollama version 0.31.2-rc1 is capable of addressing the issue. The referenced patch is 67b6a1c2d45321e0cb3c04a18073f9818de7724b.