High Memory corruption

CVE-2026-53194 — USB: serial: kl5kusb105: fix bulk-out buffer overflow

In the Linux kernel, the following vulnerability has been resolved: USB: serial: kl5kusb105: fix bulk-out buffer overflow klsi_105_prepare_write_buffer() is called by the generic write path with the bulk-out buffer and its size (bulk_out_size, 64 bytes). It stores a two-byte length header at the start of the buffer and copies the payload from the write fifo starting at buf + KLSI_HDR_LEN, but passes the full buffer size as the number of bytes to copy: count = kfifo_out_locked(&port->write_fifo, buf + KLSI_HDR_LEN, size, &port->lock); When the fifo holds at least size bytes, size bytes are copied starting two bytes into the size-byte buffer, writing KLSI_HDR_LEN bytes past its end. Copy at most size - KLSI_HDR_LEN bytes instead, leaving room for the header as safe_serial already does. Writing bulk_out_size or more bytes to the tty triggers a slab out-of-bounds write, observed with KASAN by emulating the device with dummy_hcd and raw-gadget: BUG: KASAN: slab-out-of-bounds in kfifo_copy_out+0x83/0xc0 Write of size 64 at addr ffff888112c62202 by task python3 kfifo_copy_out klsi_105_prepare_write_buffer [kl5kusb105] usb_serial_generic_write_start [usbserial] Allocated by task 139: usb_serial_probe [usbserial] The buggy address is located 2 bytes inside of allocated 64-byte region The out-of-bounds write no longer occurs with this change applied.

Published Jun 25, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.1% (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.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.15%

ahead of 4% of scored CVEs · Oct 15, 2026

Affects

Linux

Linux and 1 more

CVSS base

7.8

High · 3 source(s)

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 2.6.35≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 96d47e40bf9db4a9efd5c8fb53287a508d165f14≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < bde742b076cbe26ecc89c8c68c76ae076a524d02≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 372f33ebed747d91870f57c0a2e62884a870bffa≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 70d86e355c564b5510fde61361df014f5476c83e≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < a1288cd700f721c1a119c4f1e8efa234e59caada≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 14147b7963685957839c76ba8094924e22777d79≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 0a57320f71941d4e0b1307453c9a1f0939afe666 and 1 more ≥ 60b3013cdaf3fa8a17243ca46b19db3cbe08d943 and < 60af1fd82983c26604102e63a3fcc822c186cceb	Vulnerable	CVE Program (cve.org) e CISA ADP
Linux	Linux Kernel	version 7.1-rc5version 7.1-rc7version 7.1-rc6≥ 2.6.35 and < 5.10.259version 7.1-rc4version 7.1-rc3version 7.1-rc2version 7.1-rc1 and 6 more ≥ 6.19 and < 7.0.13≥ 6.13 and < 6.18.36≥ 6.7 and < 6.12.94≥ 6.2 and < 6.6.143≥ 5.16 and < 6.1.176≥ 5.11 and < 5.15.210	Vulnerable	NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

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	416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8	CVSS 3.1	High	—	—	Linux via CVE Program (cve.org) e CISA ADP
5.3	CVSS 3.1	Medium	1.0	4.2	0b0ca135-0b70-47e7-9f44-1890c2a1c46c 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: 416baaa9-dc9f-4396-8d5f-8c081fb06d67)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-787 · Out-of-bounds Write

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.15%

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.

endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

2026
Affected products added · linux/linux
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 7.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
Jun 25, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

11 on the record

git.kernel.org/stable/c/96d47e40bf9db4a9efd5c8fb53287a508d165f14
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/bde742b076cbe26ecc89c8c68c76ae076a524d02
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/0a57320f71941d4e0b1307453c9a1f0939afe666
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/60af1fd82983c26604102e63a3fcc822c186cceb
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/70d86e355c564b5510fde61361df014f5476c83e
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/14147b7963685957839c76ba8094924e22777d79
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/372f33ebed747d91870f57c0a2e62884a870bffa
Patch, NIST National Vulnerability Database
git.kernel.org/stable/c/a1288cd700f721c1a119c4f1e8efa234e59caada
Patch, NIST National Vulnerability Database
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53194.json
Third Party Advisory, NIST National Vulnerability Database
access.redhat.com/security/cve/CVE-2026-53194
Third Party Advisory, NIST National Vulnerability Database
bugzilla.redhat.com/show_bug.cgi
Issue Tracking, Third Party Advisory, NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Memory corruption
same class

CWE-787
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 15h
Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 15h
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-2026-53194 is "USB: serial: kl5kusb105: fix bulk-out buffer overflow", 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 0.15% 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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