CVE-2026-31622: Linux kernel · NFC: digital: Bounds check NFC-A cascade depth in SDD response handler
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 12 Nov 2026, 00:34 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 8.8 |
|---|
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 24 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
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.
References
- git.kernel.org/stable/c/9ba6bb09e00b922d902f684f575779e5433fe6e3 (opens in a new tab)
- git.kernel.org/stable/c/f83b399aa05a0712e3b1569a30d3d90b3533d2ef (opens in a new tab)
- git.kernel.org/stable/c/20663102c14566e900e1d2f679e30b7f1694f387 (opens in a new tab)
- git.kernel.org/stable/c/2819f34e08bdffb6f06a51c67948ec5737fb166a (opens in a new tab)
- git.kernel.org/stable/c/1bec5698b55aa2be5c3b983dba657c01d0fd3dbc (opens in a new tab)
- git.kernel.org/stable/c/5a59bf70c38ee1eb4be03bab830bbc3a6f0bd1f1 (opens in a new tab)
- git.kernel.org/stable/c/8d9d9bf3565271ca7ab9c716a94e87296177e7ba (opens in a new tab)
- git.kernel.org/stable/c/cc024a3de265ef6c58957f4990eccb9f806208cb (opens in a new tab)
- git.kernel.org/stable/c/46ce8be2ced389bccd84bcc04a12cf2f4d0c22d1 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)