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CVE-2026-68470
wifi: mac80211: validate extension-frame layout before RX
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem net/mac80211. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-68470 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 | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| 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
Extension frames only have the extension header at the regular 802.11 header offset. The generic RX path can still reach helpers and interface dispatch code that read regular header address fields before unsupported extension subtypes are dropped. mac80211 currently only handles S1G beacon extension frames. Drop other extension subtypes before they can reach regular-header RX processing. For S1G beacons, linearize the SKB with the management-frame path and require the fixed S1G beacon header, including optional fixed fields indicated by frame control, before generic RX dispatch. Route S1G beacons through the station/default-link RX path without regular-header station lookup. Avoid regular-header address reads in the mac80211 RX paths that process S1G extension beacons, including accept-frame, duplicate-detection, address-copy, and MLO address-translation paths. Also make ieee80211_get_bssid() length-safe before returning the S1G source-address pointer.
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/mac80211/rx.c
net/mac80211/util.c
- What this is
- MAC80211MAINTAINERS section matched on net/mac80211/ · linux-wireless@vger.kernel.org · Maintained
- Kernel module
- mac80211
Check it on the machine
grep -w CONFIG_MAC80211 /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 mac80211Prints 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.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_MAC80211
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
- 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 29.9% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/mac80211
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.10 | 6.18.57 | 1c3d9c6bd5b7 |
| 5.10 | 7.1.5 | 625fc704b19c |
| 5.10 | 7.2 | 57d503ce32ec |
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
- Malformed 802.11 extension/S1G frames reach mac80211 via the normal WiFi RX path (driver -> ieee80211_rx_list -> __ieee80211_rx_handle_packet); an attacker within radio range can inject frames over the air without routing through the Internet.
- AC:LAttack complexity, low
- The attacker fully controls crafted extension-frame length, subtype, and frame-control flags; only 4 bytes are validated before code reads up to 24 bytes of presumed 802.11 addresses, so triggering the bug is reliable and does not depend on victim-specific timing or memory layout.
- PR:NPrivileges required, none
- Exploitation requires only transmitting WiFi frames to a victim with an active mac80211 interface; no local account, capability, or association/authentication is needed because vulnerable header parsing runs before extension subtype filtering and RX handler dispatch.
- UI:NUser interaction, none
- The victim does not need to click links, join networks, or perform any deliberate action beyond having WiFi enabled; passive reception of attacker-injected extension frames on AP, STA, or mesh interfaces is sufficient to reach the vulnerable code.
- S:UScope, unchanged
- Impact is confined to kernel mac80211 RX processing on the receiving host (OOB skb reads/writes and possible crash/privilege escalation); it does not cross a VM, container, or IOMMU security boundary into another authority.
- C:HConfidentiality impact, high
- Pre-fix code reads regular-header addr1/addr2/addr3/seq_ctrl and copies 18 bytes of addrs on extension frames whose layout differs and may be shorter than 24 bytes, causing out-of-bounds reads and disclosure of adjacent skb/heap memory via ieee80211_get_bssid(), accept-frame, duplicate detection, and MLO prep paths.
- I:HIntegrity impact, high
- ieee80211_prepare_and_rx_handle can perform ether_addr_copy() MLO address translation on S1G/extension frames because ieee80211_is_beacon() is false for FTYPE_EXT, writing attacker-influenced MAC bytes into wrong skb offsets and enabling memory corruption that could be developed into arbitrary kernel write/code execution.
- A:HAvailability impact, high
- Out-of-bounds access while parsing short or malformed extension frames can provoke kernel oops/panic or destabilize RX processing; even failed exploitation still enables repeatable remote DoS against any reachable WiFi interface by retransmitting malicious extension frames.