CVE-2026-47749

CVE-2026-47749 is a high-severity vulnerability in Leejet Stable-diffusion.cpp with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

Description

stable-diffusion.cpp is a pure C/C++ library for running diffusion model (Stable Diffusion, Flux, Wan, Qwen Image, Z-Image, and more) inference. Versions prior to master-584-0a7ae07 are vulnerable to heap buffer overflow in SHORT_BINUNICODE parsing for PyTorch checkpoint files. The pickle .ckpt parser in src/model.cpp contained a heap buffer overflow vulnerability in the SHORT_BINUNICODE opcode handler. The issue was caused by sign confusion on the opcode length field. A crafted .ckpt file could trigger memcpy with a very large length derived from a negative signed value, causing immediate heap corruption. Any application using affected stable-diffusion.cpp releases to load untrusted .ckpt model files could be vulnerable. A malicious checkpoint file could cause heap corruption through memcpy with an attacker-controlled length. This may lead to process crash and could potentially be leveraged for code execution depending on heap layout. The attack requires the victim or application to load a .ckpt file from an untrusted source, such as a downloaded model from a model sharing site. The issue has been resolved in version master-584-0a7ae07. If developers are unable to immediately update their applications they can work around this issue by not loading .ckpt checkpoint files from untrusted sources, and referring to trusted model sources and safer formats such as .safetensors where possible.

Frequently asked questions

What is CVE-2026-47749?
stable-diffusion.cpp is a pure C/C++ library for running diffusion model (Stable Diffusion, Flux, Wan, Qwen Image, Z-Image, and more) inference. Versions prior to master-584-0a7ae07 are vulnerable to heap buffer overflow in SHORT_BINUNICODE parsing for PyTorch checkpoint files. The pickle .ckpt parser in src/model.cpp contained a heap buffer overflow vulnerability in the SHORT_BINUNICODE opcode handler. The issue was caused by sign confusion on the opcode length field. A crafted .ckpt file could trigger memcpy with a very large length derived from a negative signed value, causing immediate heap corruption. Any application using affected stable-diffusion.cpp releases to load untrusted .ckpt model files could be vulnerable. A malicious checkpoint file could cause heap corruption through memcpy with an attacker-controlled length. This may lead to process crash and could potentially be leveraged for code execution depending on heap layout. The attack requires the victim or application to load a .ckpt file from an untrusted source, such as a downloaded model from a model sharing site. The issue has been resolved in version master-584-0a7ae07. If developers are unable to immediately update their applications they can work around this issue by not loading .ckpt checkpoint files from untrusted sources, and referring to trusted model sources and safer formats such as .safetensors where possible.
How severe is CVE-2026-47749?
CVE-2026-47749 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-47749 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (10th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-47749?
CVE-2026-47749 affects Leejet Stable-diffusion.cpp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-47749?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-47749 have an EU (EUVD) identifier?
Yes. CVE-2026-47749 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37138.
When was CVE-2026-47749 published?
CVE-2026-47749 was published on 2026-06-16 and last updated on 2026-06-25.

References

Affected products (1)

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