# CVE-2026-31622

> Vulnerability · severity: **HIGH** (CVSS 8.8).

## Description

In the Linux kernel, the following vulnerability has been resolved:

NFC: digital: Bounds check NFC-A cascade depth in SDD response handler

The NFC-A anti-collision cascade in digital_in_recv_sdd_res() appends 3
or 4 bytes to target->nfcid1 on each round, but the number of cascade
rounds is controlled entirely by the peer device.  The peer sets the
cascade tag in the SDD_RES (deciding 3 vs 4 bytes) and the
cascade-incomplete bit in the SEL_RES (deciding whether another round
follows).

ISO 14443-3 limits NFC-A to three cascade levels and target->nfcid1 is
sized accordingly (NFC_NFCID1_MAXSIZE = 10), but nothing in the driver
actually enforces this.  This means a malicious peer can keep the
cascade running, writing past the heap-allocated nfc_target with each
round.

Fix this by rejecting the response when the accumulated UID would exceed
the buffer.

Commit e329e71013c9 ("NFC: nci: Bounds check struct nfc_target arrays")
fixed similar missing checks against the same field on the NCI path.

## Key facts

- **CVE ID:** CVE-2026-31622
- **Published:** 2026-04-24
- **CVSS severity:** HIGH
- **CVSS base score:** 8.8
- **CWE codes:** CWE-120

## Affected products

- `linux:linux_kernel`

## Primary sources

- NIST NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-31622

## Citation

> AI Analytics. CVE-2026-31622. Retrieved 2026-07-28 from https://api.ai-analytics.org/cve/CVE-2026-31622. Derived from NIST NVD. Licensed CC0.

---

*[Dataset catalog](https://api.ai-analytics.org/datasets/) · [AI Analytics](https://api.ai-analytics.org/) · CC0 1.0*