CVE-2026-64364 — HID: multitouch: fix out-of-bounds bit access on mt_io_flags
In the Linux kernel, the following vulnerability has been resolved: HID: multitouch: fix out-of-bounds bit access on mt_io_flags mt_io_flags is a single unsigned long, but mt_process_slot(), mt_release_pending_palms() and mt_release_contacts() use it as a per-slot bitmap indexed by the slot number. That slot number is only bounded by td->maxcontacts, which is taken from the device's ContactCountMaximum feature report and can be up to 255, not by BITS_PER_LONG. As a result, a multitouch device that advertises a large contact count makes set_bit()/clear_bit() operate past the mt_io_flags word and corrupt the adjacent members of struct mt_device. The sticky-fingers release timer is the easiest way to reach this. mt_release_contacts() runs for (i = 0; i < mt->num_slots; i++) clear_bit(i, &td->mt_io_flags); with num_slots == maxcontacts. For maxcontacts around 250 the loop clears the bits that overlap td->applications.next, zeroing that list head, and the list_for_each_entry() that immediately follows then dereferences NULL. The kernel panics from timer (softirq) context. On a KASAN build this shows up as a general protection fault in mt_release_contacts() with a null-ptr-deref at offset 0x58, which is offsetof(struct mt_application, num_received). The state is reachable from an untrusted USB or Bluetooth HID multitouch device; no local privileges are required. Store the per-slot active state in a separately allocated bitmap sized for maxcontacts, the same pattern already used for pending_palm_slots, and keep only MT_IO_FLAGS_RUNNING in mt_io_flags. The two "mt_io_flags & MT_IO_SLOTS_MASK" arming checks become bitmap_empty(td->active_slots, td->maxcontacts). Move MT_IO_FLAGS_RUNNING back to bit 0. It was bumped to bit 32 by the same commit to leave the low byte for the slot bits; with the slot bits gone it fits in bit 0 again, which also keeps it within the unsigned long on 32-bit.
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
- 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)
- 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)
- 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 |
version 59bd04163e6451b9c7275277882ed9f4abfa2051≥ fc488f675344931ffab6a51c43691065ec006567 and < 12e90656e330ff8bbaf2f29c535fdb8a11cc6f55≥ 77711d850bed75ae7142c3d1f22c1a8b4d049c33 and < 152983d87387f6a8ae72b73474cfa55fbcf1ec75≥ 6acfe25968913788d30ec0eedd80178c4ea3f1d0 and < b5c037d6b807017e74a115288f81bc9cd5a5aab8≥ d280c138e66be87d1fccfed42593f02fdb893905 and < a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d≥ f32fea4c0234c971c12e46d76612cdc2dd4bb046 and < e24918ee67c4dc3d20d4670750e46e9b160365f4≥ 46f781e0d151844589dc2125c8cce3300546f92a and < 37daa8c96bd563d03150e23f094cb60703594a6d≥ 46f781e0d151844589dc2125c8cce3300546f92a and < 6493ebf9489efef0105078377b973ab33d51af22 and 8 more≥ 46f781e0d151844589dc2125c8cce3300546f92a and < 8813b0612275cc61fe9e6603d0ee019247ade6be≥ 5.10.246 and < 5.10.261≥ 5.15.196 and < 5.15.212≥ 6.1.158 and < 6.1.178≥ 6.6.114 and < 6.6.145≥ 6.12.55 and < 6.12.97≥ 6.17.5 and < 6.18version 6.18 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 7.2-rc2≥ 5.10.246 and < 5.10.261version 7.2-rc1version 6.18-rc7version 6.18-rc6version 6.18-rc5version 6.18-rc4version 6.18-rc3 and 9 moreversion 6.18-rc2version 6.18≥ 6.19 and < 7.1.4≥ 6.18.1 and < 6.18.39≥ 6.17.5 and < 6.18≥ 6.12.55 and < 6.12.97≥ 6.6.114 and < 6.6.145≥ 6.1.158 and < 6.1.178≥ 5.15.196 and < 5.15.212 |
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 |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- 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 · 8.8
- 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 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/12e90656e330ff8bbaf2f29c535fdb8a11cc6f55
- git.kernel.org/stable/c/a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d
- git.kernel.org/stable/c/8813b0612275cc61fe9e6603d0ee019247ade6be
- git.kernel.org/stable/c/6493ebf9489efef0105078377b973ab33d51af22
- git.kernel.org/stable/c/e24918ee67c4dc3d20d4670750e46e9b160365f4
- git.kernel.org/stable/c/37daa8c96bd563d03150e23f094cb60703594a6d
- git.kernel.org/stable/c/152983d87387f6a8ae72b73474cfa55fbcf1ec75
- git.kernel.org/stable/c/b5c037d6b807017e74a115288f81bc9cd5a5aab8
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 12h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 12h
- 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 FIRST EPSS score.
- 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-2026-64364 is "HID: multitouch: fix out-of-bounds bit access on mt_io_flags", 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 8.8 describes technical severity. 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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