Look up another CVE · open CVE-2026-72165 in the interactive tracker
CVE-2026-72165
mtd: rawnand: fix condition in 'nand_select_target()'
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/mtd. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72165 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
'cs' here must be in range [0:nanddev_ntargets[.
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.
drivers/mtd/nand/raw/nand_base.c
- What this is
- NAND FLASH SUBSYSTEMMAINTAINERS section matched on drivers/mtd/nand/ · linux-mtd@lists.infradead.org · Maintained
- Kernel module
- nand
Check it on the machine
grep -wE 'CONFIG_MTD|CONFIG_MTD_RAW_NAND' /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 nandPrints 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.
- bookwormBnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, ppc64el/powerpc64le
- trixieBnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armel/rpi, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidBnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- B
- built in on some, a module on others, absent on the rest
- Build switches
- CONFIG_MTD, CONFIG_MTD_RAW_NAND
- 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
- 2026-08-15 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.16%, higher than 5.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/mtd
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.2 | 5.10.261 | 483a8a8581ee |
| 5.2 | 5.15.212 | c2a131fb6882 |
| 5.2 | 6.1.178 | e6df4fea1dc8 |
| 5.2 | 6.6.145 | 3da4eb15c7b4 |
| 5.2 | 6.12.97 | fbc7c8a1167b |
| 5.2 | 6.18.40 | 4bbfcf9c7e46 |
| 5.2 | 7.1.5 | 8f575fc17360 |
| 5.2 | 7.2 | 8507c2cc9e4f |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- The flaw is in the raw NAND MTD stack reached via local /dev/mtdX character-device ioctls (MEMREAD, MEMWRITE, MEMERASE, MEMSETBADBLOCK) and mtdblock I/O, not via network protocols or physical hotplug alone.
- AC:LAttack complexity, low
- An attacker with MTD device access can repeatedly issue read, write, or erase operations on multi-die NAND hardware; when a caller supplies cs equal to nanddev_ntargets(), the defective check passes deterministically and invokes the controller select_chip path.
- PR:LPrivileges required, low
- Exploitation requires local write access to the MTD character device (FMODE_WRITE on /dev/mtdX) but no capability() gate beyond device permissions; per kernel CNA guidance, PR:L is chosen when uncertain between device-permission low and root-only high privilege.
- UI:NUser interaction, none
- No separate victim interaction is required; once the attacker has access to the MTD device node they can trigger the vulnerable nand_select_target() path through their own ioctl or read/write requests.
- S:UScope, unchanged
- Impact remains within the kernel and on-board NAND controller security authority on the host; it does not cross VM, container, IOMMU, or other security-boundary scopes into a separate authority.
- C:HConfidentiality impact, high
- When cs equals nanddev_ntargets() the invalid index reaches controller select_chip handlers (denali, mtk, rockchip, renesas) that index sels[cs] without bounds checking, enabling out-of-bounds kernel memory reads.
- I:HIntegrity impact, high
- Out-of-bounds sels[cs] values are written into NAND controller CE-select and timing registers, plausibly corrupting flash contents or protection state; under the required uncertainty rule this memory-safety defect is scored as high integrity impact.
- A:HAvailability impact, high
- On legacy/default select_chip paths an out-of-range cs hits BUG(), and controller misconfiguration from invalid CE selection can oops or hang the kernel, satisfying high availability impact for kernel crash classes.