Improper input validation in the System Management Mode communications buffer allows a privileged attacker to read or write data outside the intended bounds of the Top of Memory Segment. This out‑of‑bounds access could result in loss of confidentiality or integrity of data stored in that limited memory region.

The flaw affects a wide range of AMD processors, including the EPYC 4004 and 4005, Ryzen 6000, 7000, 7040, 7045, 8000, 9000, 9000HX, AI 300, AI MAX, Embedded 7000, 8000, 9000, V3000 series, as well as the Threadripper 7000 and Threadripper PRO 7000 WX‑Series. Affected version information is not provided.

The CVSS score of 4.6 indicates moderate severity. EPSS is not available, and the vulnerability is not listed in CISA KEV catalog. The described vector requires a privileged user that can manipulate SMM communication buffers, implying that the attack is local and likely dependent on firmware or driver interaction. While it does not provide remote code execution, it can still expose sensitive data or alter memory contents within the protected segment.