Integer overflow in Ollama

CVE-2026-86289

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.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L.

Affected products

  • N/a Ollama — versions 0.31.0, 0.31.1

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-86289?
CVE-2026-86289 is a medium-severity vulnerability in Ollama, classified under CWE-189. CVSS score: 4.3/10. Published 2026-09-07.
How severe is CVE-2026-86289?
Medium severity. CVSS v3 base score is 4.3 out of 10.