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CVE-2026-80935
wifi: mt76: mt7996: bound the device EEPROM address before the EFUSE copy
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-80935 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 | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | fixedDSA-6568-1 · 2026-10-16 · text | 6.12.113-1 | Update the kernel and reboot. DSA-6568-1 shipped the fix on 2026-10-16, in 6.12.113-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
mt7996_mcu_get_eeprom() derives the destination of the EFUSE/EXT block copy from the address reported by the MCU response (event->addr, a device-controlled __le32) and clamps only the copy length, never the destination offset into dev->mt76.eeprom.data. A malicious or malfunctioning device can report an arbitrary address and drive an out-of-bounds write of up to MT7996_EXT_EEPROM_BLOCK_SIZE bytes past eeprom.data. Reject a response whose address would place the copy outside eeprom.data before deriving the destination pointer. Devices that echo the requested in-bounds offset are unaffected.
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/net/wireless/mediatek/mt76/mt7996/mcu.c
- What this is
- MEDIATEK MT76 WIRELESS LAN DRIVERMAINTAINERS section matched on drivers/net/wireless/mediatek/mt76/ · linux-wireless@vger.kernel.org · Maintained
- Kernel module
- mt7996e
Check it on the machine
grep -wE 'CONFIG_MT76_CORE|CONFIG_MT7996E|CONFIG_WLAN|CONFIG_WLAN_VENDOR_MEDIATEK' /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 mt7996ePrints 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. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switches
- CONFIG_MT76_CORE, CONFIG_MT7996E, CONFIG_WLAN, CONFIG_WLAN_VENDOR_MEDIATEK
- 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
- 2026-09-11 (37 days ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.38%, higher than 30.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.2 | 6.12.112 | 388f471ca475 |
| 6.2 | 6.18.52 | 9e5abb5e2ade |
| 6.2 | 7.2.4 | 6be59da2063d |
| 6.2 | 7.3 | 13b3c29a7820 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DSA-6568-1 | 2026-10-16 | trixie 6.12.113-1 | tracker |
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:AAttack vector, adjacent network
- The OOB copy is driven by a MediaTek Wi-Fi 7 MCU EEPROM query response (mt7996/mt7992/mt7990), not a routed IP service; the highest reasonable exposure is an adjacent attacker who can drive malicious firmware or device behavior on the local radio.
- AC:LAttack complexity, low
- A malicious MCU response can set event->valid and an arbitrary event->addr; the host then memcpy's up to MT7996_EXT_EEPROM_BLOCK_SIZE (1024) device-controlled bytes to eeprom.data+addr with no race or other condition beyond attacker control.
- PR:NPrivileges required, none
- MCU EEPROM responses are consumed in mt7996_eeprom_load() during driver bring-up with no OS credential, capability, or Wi-Fi authentication check; an adjacent attacker needs no local account.
- UI:NUser interaction, none
- The copy runs automatically in mt7996_eeprom_load() during pci_probe/register after firmware load; no victim action such as mounting a filesystem or opening a file is required.
- S:UScope, unchanged
- The write corrupts host kernel heap around the mt76 EEPROM buffer and is standard kernel memory corruption, not a VM escape, IOMMU bypass, or other crossed security authority.
- C:HConfidentiality impact, high
- Attacker-controlled destination offset and payload are kernel memory corruption that can overwrite adjacent objects and pointers and be leveraged for information disclosure, so confidentiality impact is high.
- I:HIntegrity impact, high
- Up to 1024 bytes of device-controlled data are written at a device-chosen offset past the 7680-byte eeprom.data allocation, an out-of-bounds write primitive that can yield arbitrary kernel writes or control-flow hijacking.
- A:HAvailability impact, high
- An unbounded kernel heap write during EEPROM init can oops, panic, or hang the host, a high availability impact on Wi-Fi 7 APs, routers, and workstations.