CVE-2026-90221 nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing
A local attacker can trigger uninitialized memory reads in the Linux kernel NFC subsystem, potentially disclosing sensitive kernel memory contents.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90221?
CVE-2026-90221 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
nfc: nci: fix use of uninitialized memory in CORE_INIT_RSP parsing
nci_core_init_rsp_packet_v1() and nci_core_init_rsp_packet_v2() parse the CORE_INIT_RSP packet without validating that the skb contains enough data. A malformed response (e.g. injected via virtual_ncidev) can declare a large num_supported_rf_interfaces while providing insufficient data, causing reads of uninitialized slab memory. This is later used in nci_init_complete_req(), triggering a KMSAN uninit-value warning.
Add skb length checks before accessing packet fields: - Validate the skb has at least 1 byte for the status field. - Validate the skb can hold the fixed-size header before parsing. - In v2, bounds-check each variable-length rf_interface entry and its extension parameters within the parsing loop. - In v1, verify the skb is large enough for both the variable-length rf_interfaces array and the trailing rsp_2 structure.
Which versions are affected by CVE-2026-90221?
How do I fix CVE-2026-90221?
Apply the vendor's patch.
Is CVE-2026-90221 being exploited?
There is no known exploitation of CVE-2026-90221 in the wild and no public exploit code.
Sources
Also known as AZL-102122, BELL-CVE-2026-90221, DEBIAN-CVE-2026-90221, GHSA-h298-hpmc-3w4v, UBUNTU-CVE-2026-90221.