CVE-2026-46213 — HID: appletb-kbd: fix UAF in inactivity-timer cleanup path
In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: fix UAF in inactivity-timer cleanup path Commit 38224c472a03 ("HID: appletb-kbd: fix slab use-after-free bug in appletb_kbd_probe") added timer_delete_sync(&kbd->inactivity_timer) to both the probe close_hw error path and appletb_kbd_remove(), but the way it was wired in left the inactivity timer reachable during driver tear-down via two distinct windows. Window A -- put_device() before timer_delete_sync(): put_device(&kbd->backlight_dev->dev); timer_delete_sync(&kbd->inactivity_timer); The inactivity_timer softirq reads kbd->backlight_dev and calls backlight_device_set_brightness() -> mutex_lock(&ops_lock). If a concurrent hid_appletb_bl unbind drops the last devm reference between these two calls, the backlight_device is freed and the mutex_lock() touches freed memory. Window B -- backlight cleanup before hid_hw_stop(): if (kbd->backlight_dev) { timer_delete_sync(...); put_device(...); } hid_hw_close(hdev); hid_hw_stop(hdev); Even after Window A is closed, hid_hw_close()/hid_hw_stop() still run afterwards, so a late ".event" callback from the HID core (USB URB completion on real Apple hardware) can arrive after timer_delete_sync() drained the softirq but before put_device() drops the reference. That callback reaches reset_inactivity_timer(), which calls mod_timer() and re-arms the timer. The freshly re-armed timer can then fire on the about-to-be-freed backlight_device. Both windows produce the same KASAN slab-use-after-free: BUG: KASAN: slab-use-after-free in __mutex_lock+0x1aab/0x21c0 Read of size 8 at addr ffff88803ee9a108 by task swapper/0/0 Call Trace: <IRQ> __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq handle_softirqs Allocated by task N: devm_backlight_device_register appletb_bl_probe Freed by task M: (concurrent hid_appletb_bl unbind path) Close both windows at once by reworking the tear-down in appletb_kbd_remove() and in the probe close_hw error path so that 1) hid_hw_close()/hid_hw_stop() run before the backlight cleanup, guaranteeing no further .event callback can fire and re-arm the timer, and 2) inside the "if (kbd->backlight_dev)" block, timer_delete_sync() runs before put_device(), so the softirq is drained before the final reference is dropped.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 38224c472a038fa9ccd4085511dd9f3d6119dbf9 and < 59a79938ca5541fe55d675304116b7ea684afef0≥ 38224c472a038fa9ccd4085511dd9f3d6119dbf9 and < 93d989e47bc316c793a69c6a332e053c90e29f02≥ 38224c472a038fa9ccd4085511dd9f3d6119dbf9 and < 4db2af929279c799b5653a39eb0795c72baffca4version 51720dee3a61ebace36c3dcdd0b4a488e0970f29≥ 6.15.6 and < 6.16version 6.16 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 6.15.6 and < 6.16≥ 6.16.1 and < 6.18.32≥ 6.19 and < 7.0.9version 6.16version 6.16-rc5version 6.16-rc6version 6.16-rc7version 7.1-rc1 and 2 moreversion 7.1-rc2version 7.1-rc3 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.17%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
3 on the record
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 9h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 9h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-46213 is "HID: appletb-kbd: fix UAF in inactivity-timer cleanup path", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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