Look up another CVE · open CVE-2026-68125 in the interactive tracker
CVE-2026-68125
mac802154: llsec: reject frames shorter than the authentication tag
Published 2026-08-10 (2 months ago) by the Linux kernel CNA. Subsystem net/mac802154. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-68125 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 | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.101-1 | Update the kernel and reboot. Fixed in 6.12.101-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.6-1 | Update the kernel and reboot. Fixed in 7.1.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4745-1 · 2026-08-18 · text | 6.12.101-1~deb12u1 | Update the kernel and reboot. DLA-4745-1 shipped the fix on 2026-08-18, in 6.12.101-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
llsec_do_decrypt_auth() computes the associated-data length for the AEAD request as assoclen += datalen - authlen; where datalen is the number of bytes after the MAC header and authlen (4, 8 or 16) is the length of the authentication tag. Nothing verifies that the frame actually carries at least authlen payload bytes. A secured frame whose payload is shorter than the tag makes datalen - authlen negative; assoclen is then passed to aead_request_set_ad() as an unsigned value close to 4 GiB, so crypto_aead_decrypt() walks far off the end of the scatterlist that only spans the real frame. The frame is fully attacker-controlled and reaches this path from any IEEE 802.15.4 peer in radio range. Reject frames whose payload is shorter than the authentication tag before the subtraction. Dynamically reproduced on a KASAN kernel as a general-protection-fault in the AEAD scatterwalk, and the fix confirmed.
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/mac802154/llsec.c
- What this is
- IEEE 802.15.4 SUBSYSTEMMAINTAINERS section matched on net/mac802154/ · linux-wpan@vger.kernel.org · Maintained
- Kernel module
- mac802154
Check it on the machine
grep -w CONFIG_MAC802154 /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 mac802154Prints 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.
- bookworm, trixie, forky, sid, bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_MAC802154
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
- 2026-08-10 (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
- 0.32%, higher than 23.0% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/mac802154
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 3.16 | 5.10.265 | f27ce82eb049 |
| 3.16 | 5.15.216 | 2d6b42a61373 |
| 3.16 | 6.1.183 | ec7e62d77193 |
| 3.16 | 6.6.148 | 5bbf0cd9b6a7 |
| 3.16 | 6.12.101 | de80808f37d9 |
| 3.16 | 6.18.42 | f20dedce0429 |
| 3.16 | 7.1.6 | e09e0301d616 |
| 3.16 | 7.2 | fd3a3f28ed60 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | tracker |
| DLA-4745-1 | 2026-08-18 | bookworm 6.12.101-1~deb12u1 | 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
- Exploitation requires sending crafted IEEE 802.15.4 frames over the WPAN radio interface; any peer within RF range can reach mac802154 receive/decrypt without IP routing or local shell access, matching Adjacent wireless attack guidance like Bluetooth.
- AC:LAttack complexity, low
- The attacker fully controls frame length and security header fields; once LLSEC is enabled on the victim, a single undersized MIC-only secured frame reliably triggers the assoclen underflow and was dynamically reproduced as a KASAN GPF.
- PR:NPrivileges required, none
- No Linux credentials or capabilities are required on the target; exploitation is performed by an over-the-air 802.15.4 peer spoofing a known PAN device/key/frame counter, not via local syscalls, ioctl, or netlink.
- UI:NUser interaction, none
- No victim user action is needed beyond normal operation of an LLSEC-enabled 802.15.4 interface; the malicious frame is processed automatically in the softirq receive path before delivery to userspace.
- S:UScope, unchanged
- Impact is confined to kernel memory and availability on the attacked host's WPAN stack; it does not cross a VM, container, or IOMMU security boundary into a separate authority.
- C:HConfidentiality impact, high
- The wrapped assoclen makes crypto_aead_decrypt() scatterwalk read gigabytes beyond the skb-backed scatterlist, causing out-of-bounds kernel memory reads that can disclose adjacent heap or slab data and enable further exploitation primitives.
- I:HIntegrity impact, high
- Kernel memory corruption in the AEAD decrypt scatterwalk path can be leveraged for control-flow hijack or arbitrary write primitives beyond the demonstrated crash, consistent with high integrity impact for exploitable OOB access in crypto handlers.
- A:HAvailability impact, high
- The bug was reproduced on a KASAN kernel as a general-protection fault in the AEAD scatterwalk, and repeated malicious frames can panic or hang the kernel on LLSEC-enabled coordinators, gateways, and IoT border routers.