A heap out‑of‑bounds read in Blender's read_struct() allows a crafted .blend file to read beyond allocated memory. If the SDNA struct layout matches, the function skips size validation, causing field reads, writes, and pointer dereferences to overrun heap memory. The result can be a crash or, under the right conditions, arbitrary code execution. This is a classic out‑of‑bounds access (CWE‑125).

The flaw affects Blender versions released before 4.5.15 and before the 5.x series 5.2.3. All editions of the Blender Foundation product built with those versions are vulnerable. The patch is available in later releases.

The CVSS score of 8.5 classifies the issue as high severity. Because the exploit requires a carefully crafted .blend file presented to a user, the vector is likely local or remote delivery of a malicious file. No publicly available exploit is listed, and the vulnerability is not yet classified in the CISA KEV catalog. Nonetheless, the lack of size validation and the potential for code execution make it a serious risk for anyone who imports untrusted files in this version set.