CVE-2026-80796

What the bug is

nci_extract_activation_params_iso_dep() and nci_extract_activation_params_nfc_dep() read an inner length byte from the NCI RF_INTF_ACTIVATED_NTF payload and use it to memcpy() into fixed kernel buffers, but neither function receives the caller-validated activation_params_len. A crafted NCI notification with activation_params_len=1 and an inner length byte of up to 20 (NFC-A) or 50 (NFC-B) causes memcpy() to read that many bytes past the one valid byte in the activation params region -- a slab out-of-bounds read of kernel memory adjacent to the NCI skb. The sibling nci_extract_rf_params_*() family was given equivalent protection by commit 571dcbeb8e63 ("net: nfc: nci: Fix parameter validation for packet data"), but the two activation parameter extractors were not updated at that time. Add a data_len parameter to both functions, guard against an empty region before consuming the inner length byte, decrement the remaining count after consuming it, and clamp the copy length to what is actually available. Update both call sites to pass ntf.activation_params_len, which is already validated against the skb at ntf.c:801.

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

net/nfc/nci/ntf.c

What this is

NFC SUBSYSTEMMAINTAINERS section matched on net/nfc/ · oe-linux-nfc@lists.linux.dev · Maintained

Kernel module

nci

Check it on the machine

grep -wE 'CONFIG_NFC|CONFIG_NFC_NCI' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w nci

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_NFC, CONFIG_NFC_NCI

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2026-09-04 (44 days ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.19%, higher than 8.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

not yet assignedsource

Subsystem

net/nfc

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
3.3	5.10.269	1168484fe2b3
3.3	5.15.220	be311c0cfead
3.3	6.1.187	04e51353cb9f
3.3	6.6.156	e25b44bd8b8c
3.3	6.12.108	9b01f5af0dc5
3.3	6.18.47	9620a91f8d64
3.3	7.1.11	cf9d44be50b9
3.3	7.2.1	f5c534b53f8c
3.3	7.3	0428fa2c22e2

Debian advisories