Buffer overflow in Leejet Stable-Diffusion.cpp
CVE-2026-70659
stable-diffusion.cpp is a pure C/C++ library for running diffusion model (Stable Diffusion, Flux, Wan, Qwen Image, Z-Image, and more) inference. From master-742-1a13107 until master-763-4fcc6fe, IMatrixCollector::load_imatrix in src/runtime/imatrix.cpp reuses the values and counts vectors for entries with the same tensor name but resizes them only when they are empty. An untrusted .imatrix file can provide a small nval for the first entry and a larger nval for a second entry with the same name, causing the accumulation loop to write attacker-controlled floating-point and integer values beyond both heap buffers. Loading the file through the --imat-in conversion path can corrupt the heap or crash the process before a model is required. This issue is fixed in master-763-4fcc6fe.
Vulnerability class: Buffer Overflow
Published .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Leejet Stable-Diffusion.cpp — versions < master-763-4fcc6fe
Weakness classification (CWE)
References
- https://github.com/leejet/stable-diffusion.cpp/commit/4fcc6fef10c6f686801c6e257b22cd6a3deb906b
- https://github.com/leejet/stable-diffusion.cpp/pull/1750
- https://github.com/leejet/stable-diffusion.cpp/releases/tag/master-763-4fcc6fe
- https://github.com/leejet/stable-diffusion.cpp/security/advisories/GHSA-6q7q-2v9c-x8m7
Frequently asked questions
- What is CVE-2026-70659?
- CVE-2026-70659 is a high-severity vulnerability in Leejet Stable-Diffusion.cpp, classified under Out-of-bounds Write. CVSS score: 7.8/10. Published 2026-11-05.
- How severe is CVE-2026-70659?
- High severity. CVSS v3 base score is 7.8 out of 10.