NVD / CVE Program· CNA Linux

CVE-2026-68409: wifi: mac80211: defer link RX stats percpu free to RCU

Noroxi assessment

Priority: Monitor (action score 35/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 2aa1789880fa5e41049b0f6a74a4fc2fa1997610, a03fceae0c65b31ce31840dac5e26684ceecb65b, a5afc00280986063f1c355821544fabbb2a960f7; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2aa1789880fa5e41049b0f6a74a4fc2fa1997610, a03fceae0c65b31ce31840dac5e26684ceecb65b, a5afc00280986063f1c355821544fabbb2a960f7; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: defer link RX stats percpu free to RCU sta_remove_link() frees a removed MLO link's RX stats percpu buffer right away, but defers only the link container to RCU: sta_info_free_link(&alloc->info); kfree_rcu(alloc, rcu_head); The RX fast path reads link_sta under rcu_read_lock and writes the percpu stats. A reader that resolved link_sta before the removal keeps the pointer. The container stays alive from the kfree_rcu, so the read still works. But the percpu block it points to is already freed. This needs uses_rss. That is when pcpu_rx_stats exists. The full STA teardown frees the deflink stats only after synchronize_net(). The link removal path had no such barrier. The race is hard to win in practice, but the free should still wait for RCU. Free the link together with its data from a single RCU callback, so the percpu block is reclaimed only after readers drain.

HighCVSS 8.8 · v3.1—No exploit Fix available

Published: Aug 10, 2026
Updated: Oct 30, 2026
EPSS: 0.3% · 23th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 8.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 6.0affected
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before acd5931d5adf12f0163f83dc00320e7011f4da92affected · git
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before a5afc00280986063f1c355821544fabbb2a960f7affected · git
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before b679c1cffb2f3d0854b8b05ea9e909ad6489046faffected · git
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before 2aa1789880fa5e41049b0f6a74a4fc2fa1997610affected · git
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before a03fceae0c65b31ce31840dac5e26684ceecb65baffected · git
- c71420db653aba30a234d1e4cf86dde376e604fa and later · before aa2eb62525188269cdd402a583b9a8ed94657ff0affected · git
- before 6.0not affected · semver
- 6.1.191 and later · up to and including 6.1.*not affected · semver
- 6.6.160 and later · up to and including 6.6.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	bpftool	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-abi-stablelists	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-core	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-cross-headers	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-debug	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-debug-core	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-debug-devel	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-debug-modules	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-debug-modules-extra	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-devel	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-doc	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-headers	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-modules	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-modules-extra	before 4.18.0-553.173.1.el8_10	4.18.0-553.173.1.el8_10
AlmaLinux:8	kernel-rt	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-core	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-debug	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-debug-core	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-debug-devel	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-debug-modules	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-debug-modules-extra	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-devel	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10
AlmaLinux:8	kernel-rt-modules	before 4.18.0-553.173.1.rt7.514.el8_10	4.18.0-553.173.1.rt7.514.el8_10

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
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CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
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CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
40Plan

Published before and after this one in the same product

← EarlierCVE-2026-68406Aug 10, 2026 · wifi: cfg80211: validate PMSR FTM preamble range
0Monitor
← EarlierCVE-2026-68408Aug 10, 2026 · wifi: cfg80211: convert pmsr_free_wk to wiphy_work to fix deadlock
0Monitor
Later →CVE-2026-68410Aug 10, 2026 · wifi: libertas: fix memory leak in helper_firmware_cb()
0Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	2aa1789880fa5e41049b0f6a74a4fc2fa1997610	Vendor (CNA)
Linux Linux	a03fceae0c65b31ce31840dac5e26684ceecb65b	Vendor (CNA)
Linux Linux	a5afc00280986063f1c355821544fabbb2a960f7	Vendor (CNA)
Linux Linux	aa2eb62525188269cdd402a583b9a8ed94657ff0	Vendor (CNA)
Linux Linux	acd5931d5adf12f0163f83dc00320e7011f4da92	Vendor (CNA)
Linux Linux	b679c1cffb2f3d0854b8b05ea9e909ad6489046f	Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0	—	Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0	6.6.161.1-1 · Release Notes	Microsoft (MSRC)
almalinux:bpftool	4.18.0-553.173.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel	4.18.0-553.173.1.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-core	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-core	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-devel	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-modules	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-debug-modules-extra	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-devel	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-modules	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
almalinux:kernel-rt-modules-extra	4.18.0-553.173.1.rt7.514.el8_10 · AlmaLinux:8	Package registry (OSV)
debian:linux	6.12.115-2 · Debian:13	Package registry (OSV)
debian:linux	7.1.6-1 · Debian:14	Package registry (OSV)
red hat:kernel-rt	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-core	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-core	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-debuginfo	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)
red hat:kernel-rt-debug-devel	0:4.18.0-553.173.1.rt7.514.el8_10 · Red Hat:enterprise_linux:8::nfv	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-681170 days aparttipc: clear sock->sk on the failed-insert path in tipc_sk_create()
39Monitor
CVE-2026-681270 days apartila: reload IPv6 header after pskb_may_pull in checksum adjust
39Monitor
CVE-2026-681440 days apartphonet: pep: fix use-after-free in pep_get_sb()
39Monitor
CVE-2026-681560 days apartlibceph: refresh auth->authorizer_buf{,_len} after authorizer update
39Monitor
CVE-2026-683810 days apartksmbd: pin conn during async oplock break notification
39Monitor
CVE-2026-684260 days apartxfrm: fix stale skb->prev after async crypto steals a GSO segment
39Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0800 · Aug 11, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Someone on the same network segment can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Adjacent
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

SSVC exploitation— → noneOct 16, 2026, 5:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/2aa1789880fa5e41049b0f6a74a4fc2fa1997610

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records