A flaw in the Linux kernel’s CAAM crypto driver occurs when a key longer than the block size is supplied for HMAC encryption. The driver copies the key into a buffer that was intended to be aligned for DMA, but the allocation did not use the correct rounding, so the hashed key was written to memory that could overlap neighboring addresses. This misaligned write can corrupt kernel memory, which could lead to instability or data loss, and in some scenarios might allow privilege escalation if the attacker can influence the key value (inferred from the nature of the memory corruption).

The vulnerability exists in the CAAM module of the Linux kernel. Any kernel build that includes this driver is potentially affected. The fix is upstream in the mainline kernel and will be present in future releases once merged; based on the commit references provided, it appears the fix has been committed to the mainline kernel, but the CVE payload does not explicitly state that it has been merged.

The CVSS score of 7.8 indicates medium‑to‑high severity for uncontrolled memory writes. The EPSS score of < 1% indicates very low exploitation probability, and the issue is not listed in the CISA KEV catalog. The likely attack vector requires the attacker to provide a long HMAC key that reaches the CAAM driver; this generally necessitates local execution or elevated privileges (based on the description, it is inferred that the attacker must have access to influence key values). Based on the description, it is inferred that remote exploitation is unlikely unless an attacker can achieve local code execution or inject data that touches the CAAM interface.