CVE-2026-70659
An inconsistent importance matrix could corrupt memory during model conversion
stable-diffusion.cpp project · stable-diffusion.cpp importance-matrix loader
First documented disclosure · Review checkpoint
Summary
A conversion job could write outside its allocated memory when reading an untrusted importance-matrix file.
Severity and exploitation evidence
High · 7.8/10 · CVSS 3.1. Severity source.
Exploitation not established: The reviewed sources describe the vulnerability and its conditions. They do not identify malicious exploitation.
Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.
How the weakness works
The conversion loader did not consistently validate tensor metadata against its allocated memory.
Conditions required
A conversion worker processes an untrusted importance-matrix file.
Potential impact
The conversion process could crash or suffer heap corruption. The project does not establish malicious code execution.
Affected versions and configurations
From master-742-1a13107 up to master-763-4fcc6fe, exclusive.
Fix and mitigation status
master-763-4fcc6fe.
Practical next steps
Use build master-763-4fcc6fe or later and restrict which importance matrices conversion workers accept.
Operating lesson
Validate tensor metadata against the available buffer before writing.
Evidence and limits
The public fix proposal preceded the July 6 fixed build and September 27 security advisory.
Sources
- stable-diffusion.cpp project | An inconsistent importance matrix could corrupt memory during model conversion
Primary source ·
- GitHub_M CVE record
Primary source ·
- Project security advisory and affected range
Primary source ·