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CVE-2026-53182
wifi: nl80211: reject oversized EMA RNR lists
Published 2026-06-25 (4 months ago) by the Linux kernel CNA. Subsystem net/wireless. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-53182 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-4665-1 · 2026-07-03 · text | 6.1.176-1 | Update the kernel and reboot. DLA-4665-1 shipped the fix on 2026-07-03, in 6.1.176-1. A running kernel keeps the old code until the machine restarts. |
| 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 | 7.0.13-1 | Update the kernel and reboot. Fixed in 7.0.13-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.13-1 | Update the kernel and reboot. Fixed in 7.0.13-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
nl80211_parse_rnr_elems() stores the parsed element count in a u8-backed cfg80211_rnr_elems::cnt field and uses that count to size the flexible array allocation. Reject nested NL80211_ATTR_EMA_RNR_ELEMS input once the count reaches 255, before incrementing it again. This keeps the parser aligned with the data structure it fills and matches the existing bound check used by nl80211_parse_mbssid_elems().
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/wireless/nl80211.c
- What this is
- 802.11 (including CFG80211/NL80211)MAINTAINERS section matched on net/wireless/ · linux-wireless@vger.kernel.org · Maintained
- Kernel module
- cfg80211
Check it on the machine
grep -wE 'CONFIG_CFG80211|CONFIG_WIRELESS' /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 cfg80211Prints 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 switches
- CONFIG_CFG80211, CONFIG_WIRELESS
- 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
- 2026-06-25 (4 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.13%, higher than 2.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/wireless
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 6.1.160 | 6.1.176 | fc0ec2fc02df |
| 6.4 | 6.6.143 | 688fcac7054a |
| 6.4 | 6.12.94 | 30c3fa80f423 |
| 6.4 | 6.18.36 | 265c07c09c83 |
| 6.4 | 7.0.13 | ecbf3c45add3 |
| 6.4 | 7.1 | 4cd92957e8f8 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4671-1 | 2026-07-05 | bullseye 6.1.176-1~deb11u1 | tracker |
| DLA-4665-1 | 2026-07-03 | bookworm 6.1.176-1 | 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:LAttack vector, local
- The vulnerable parser is reached through local nl80211 generic-netlink commands that configure AP beacon data, not by received WiFi frames or remote network traffic.
- AC:LAttack complexity, low
- An attacker who can send the command can deterministically provide 256 or more nested EMA RNR elements; there is no race or condition outside the attacker's control beyond targeting an affected AP-capable configuration.
- PR:LPrivileges required, low
- The commands require CAP_NET_ADMIN via GENL_UNS_ADMIN_PERM, which is checked in the relevant network namespace; under kernel scoring guidance this is low privilege because CAP_NET_ADMIN may be available through user namespaces.
- UI:NUser interaction, none
- No victim action is required after the attacker sends the crafted nl80211 request.
- S:UScope, unchanged
- The corruption occurs inside the kernel and impacts the same kernel security authority; it is not a VM escape or other cross-scope boundary violation.
- C:HConfidentiality impact, high
- The u8 count wrap causes an undersized flexible-array allocation followed by attacker-influenced out-of-bounds heap writes, which is memory corruption plausibly usable for kernel memory disclosure.
- I:HIntegrity impact, high
- The bug is a kernel heap out-of-bounds write of RNR element metadata past the allocation, making arbitrary corruption or control-flow compromise defensible.
- A:HAvailability impact, high
- The same heap corruption can readily crash or panic the kernel even if not weaponized for code execution.