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CVE-2026-64515
wifi: mac80211: fix MLE defragmentation
Published 2026-07-25 (3 months ago) by the Linux kernel CNA. Subsystem net/mac80211. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-64515 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 | fixed | 6.12.94-1 | Update the kernel and reboot. Fixed in 6.12.94-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.12-1 | Update the kernel and reboot. Fixed in 7.0.12-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
If either reconf or EPCS multi-link element (MLE) is contained in a non-transmitted profile, the defragmentation routine is called with a pointer to the defragmented copy, but the original elements. This is incorrect for two reasons: - if the original defragmentation was needed, it will not find the correct data - if the original frame is at a higher address, the parsing will potentially overrun the heap data (though given the layout of the buffers, only into the new defragmentation buffer, and then it has to stop and fail once that's filled with copied data. Fix it by tracking the container along with the pointer and in doing so also unify the two almost identical defragmentation routines.
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/parse.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. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixie, 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 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
- 2026-07-25 (3 months ago)source
- CVSS
- 8.3 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.24%, higher than 13.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- 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 |
|---|---|---|
| 6.9 | 6.12.92 | 1f573e17bcb7 |
| 6.9 | 6.18.34 | 55c479aae99b |
| 6.9 | 7.0.11 | 722b3f86df80 |
| 6.9 | 7.1 | a74e893f30db |
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
- An attacker within radio range can inject spoofed WiFi beacons containing the crafted MBSSID profile and MLE. This is an adjacent-network attack.
- AC:LAttack complexity, low
- The required EHT non-transmitted-BSS state is a vulnerable deployment condition, while the attacker controls the element layout and can repeatedly transmit trigger frames. No uncontrollable race must be won.
- PR:NPrivileges required, none
- The receive path has no capability, namespace, login, or protocol-authentication requirement. Unauthenticated beacons are processed unless optional beacon protection is enabled.
- UI:NUser interaction, none
- An associated or associating station processes received beacons automatically. No contemporaneous victim action is required.
- S:UScope, unchanged
- The vulnerable parser and the affected kernel networking and link-management resources share the same security authority. There is no VM, sandbox, or IOMMU boundary crossing.
- C:HConfidentiality impact, high
- The wrong container bound permits a nontrivial out-of-bounds read past the logical profile into heap scratch data. Although the current layout confines traversal within the allocation, the overread is not strictly limited to a few bytes, requiring C:H under the specified guidance.
- I:LIntegrity impact, low
- Destination bounds prevent an arbitrary-address heap write or credible control-flow primitive. Incorrectly reconstructed or truncated MLE data can nevertheless cause limited unauthorized changes to MLO link-removal or QoS state.
- A:HAvailability impact, high
- Repeated unauthenticated beacon injection can keep MLE parsing and link reconfiguration failing or remove usable links. In a WiFi-dependent device this can cause complete, persistent network-service loss.