CVE-2026-86289 Ollama GGUF Decoder gguf.go readGGUFV1String integer overflow
Remote attackers can trigger an integer overflow in the GGUF decoder, potentially causing denial of service or code execution in Ollama.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-86289?
CVE-2026-86289 is a medium-severity vulnerability in Ollama, published on 7 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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.
Which versions are affected by CVE-2026-86289?
How do I fix CVE-2026-86289?
No fix has been published for CVE-2026-86289 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-86289 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86289 exists.
Sources
Also known as GHSA-c2q9-58w2-gjg4.