The pn532 UART driver in the Linux kernel was allowed to append every incoming byte to an skb without resetting the buffer until a complete frame was detected. A continuous stream of bytes that does not contain a valid PN532 frame header would thus cause the skb to grow until it exceeded the tail limit, leading to memory exhaustion or a buffer overflow in the kernel. The fix clamps the receive buffer so that malformed UART traffic cannot expand the skb beyond PN532_UART_SKB_BUFF_LEN, preventing the kernel from being corrupted or crashed by malicious data.

Any Linux kernel installation that contains the pn532 NFC driver and is running a version prior to the patch is potentially affected. Because the vendor list is generic (Linux:Linux) the precise affected releases are not enumerated in the available data, but all active kernel branches that ship the pn532 driver could be impacted if they have not yet applied the update.

The CVSS and EPSS metrics are not available, and the vulnerability is not listed in CISA’s KEV catalog, indicating no publicly known exploit or active exploitation activity at the time of this analysis. The attack vector is inferred to be local or device‑controlled, requiring an adversary to send a crafted stream of UART data to the NFC device. If successfully leveraged, the flaw could exhaust kernel memory and cause a system crash, resulting in a denial of service. Exploit feasibility is uncertain but consideration of the attacker’s physical or device access is warranted.