Look up another CVE · open CVE-2026-64030 in the interactive tracker
CVE-2026-64030
wifi: mac80211: bounds-check link_id in ieee80211_ml_epcs
Published 2026-07-19 (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-2026-64030 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 | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| 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
IEEE80211_MLE_STA_EPCS_CONTROL_LINK_ID is 0x000f, so link_id extracted from a PRIO_ACCESS ML element PER_STA_PROFILE subelement can be 0..15. sdata->link[] has IEEE80211_MLD_MAX_NUM_LINKS (15) entries (indices 0..14), making index 15 out-of-bounds. A connected WiFi 7 AP can trigger this by sending an EPCS Enable Response action frame with a PER_STA_PROFILE subelement where link_id = 15. The unsolicited-notification path (dialog_token = 0) is reachable any time EPCS is already enabled, without any prior client request. sdata->link[15] reads into the first word of sdata->activate_links_work (a wiphy_work whose embedded list_head is non-NULL after INIT_LIST_HEAD), so the NULL check on the result does not catch the invalid access. The garbage pointer is then passed to ieee80211_sta_wmm_params(), which dereferences link->sdata and crashes the kernel. The same class of bug was fixed for ieee80211_ml_reconfiguration() by commit 162d331d833d ("wifi: mac80211: bounds-check link_id in ieee80211_ml_reconfiguration").
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/mlme.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
- 2026-07-19 (3 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
- 0.24%, higher than 13.9% 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 |
|---|---|---|
| 6.15 | 6.18.34 | 2d8379834800 |
| 6.15 | 7.0.11 | 863f1f02a3bd |
| 6.15 | 7.1 | f718506edd2d |
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
- A malicious or compromised WiFi 7 AP transmits a crafted EPCS Enable Response action frame over the wireless link; exploitation requires proximity on the same WiFi segment, not remote internet reachability.
- AC:LAttack complexity, low
- Once a victim WiFi 7 MLD station is associated with an EPCS-capable AP, the attacker reliably triggers the bug by setting link_id=15 in a PER_STA_PROFILE subelement, including via the unsolicited notification path (dialog_token=0) when EPCS is already enabled.
- PR:NPrivileges required, none
- The attacker acts as the associated AP sending forged management frames and needs no local privileges, accounts, or capabilities on the victim system.
- UI:NUser interaction, none
- After association and EPCS enablement, the kernel processes the malicious frame automatically with no further victim action required at exploit time.
- S:UScope, unchanged
- Impact is confined to kernel memory corruption and crash on the victim station; it does not cross a VM, IOMMU, or sandbox security boundary.
- C:HConfidentiality impact, high
- Out-of-bounds read of sdata->link[15] pulls a kernel pointer from adjacent sdata->activate_links_work memory, and the resulting bogus pointer is dereferenced as ieee80211_link_data, constituting an unbounded kernel memory read primitive.
- I:HIntegrity impact, high
- The out-of-bounds pointer is used as a valid ieee80211_link_data structure; if execution proceeds past the initial dereference, _ieee80211_sta_wmm_params() can write to link->tx_conf[] at incorrect offsets, enabling potential kernel memory corruption beyond a simple fault.
- A:HAvailability impact, high
- The invalid pointer dereference in ieee80211_sta_wmm_params() causes a kernel oops/panic, resulting in complete loss of availability for the victim system.