CVE-2026-86289 Ollama CVE debrief

Who should care

Defenders responsible for Ollama installations should assess exposure and potential impact. System administrators and security teams should verify versions and apply patches as needed.

Why it matters

Defenders should prioritize verifying exposure of Ollama installations to this vulnerability and assess the potential impact of an integer overflow in the GGUF Decoder component. The corpus does not establish versions, exploitation, impact, or remediation beyond upgrading to 0.31.2-rc1.

• Verification of Ollama installations for exposure to this vulnerability
• Assessment of potential impact of an integer overflow in the GGUF Decoder component
• Upgrade to version 0.31.2-rc1 or later if vulnerable

Technical summary

The vulnerability affects the function readGGUFV1String of the file fs/ggml/gguf.go of the component GGUF Decoder in Ollama up to version 0.31.1. An integer overflow occurs when performing a manipulation, allowing a remote attack. The exploit has been made public. Defenders should verify Ollama installations for exposure and assess potential impact. Upgrading to version 0.31.2-rc1 is recommended to address this issue. The vulnerability allows for a remote attack, and defenders should prioritize verifying exposure and assessing potential impact.

Defensive priority

Defenders should prioritize verifying exposure of Ollama installations to this vulnerability and assess the potential impact of an integer overflow in the GGUF Decoder component.

Recommended defensive actions

• Verify Ollama installations for exposure to this vulnerability
• Assess the potential impact of an integer overflow in the GGUF Decoder component
• Upgrade to version 0.31.2-rc1 or later if vulnerable
• Perform a thorough review of system logs to detect potential exploitation attempts
• Implement additional monitoring to identify suspicious activity related to Ollama
• Conduct a thorough asset inventory to identify all instances of Ollama
• Establish a rollback plan in case of issues with the upgrade

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description, affected versions, and available patch. However, the corpus does not establish versions, exploitation, impact, or remediation beyond upgrading to 0.31.2-rc1.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.