FKIE_CVE-2026-53194
Vulnerability from fkie_nvd - Published: 2026-06-25 09:16 - Updated: 2026-06-30 14:44
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0 (High) - CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/usb/serial/kl5kusb105.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "60af1fd82983c26604102e63a3fcc822c186cceb",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "0a57320f71941d4e0b1307453c9a1f0939afe666",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "14147b7963685957839c76ba8094924e22777d79",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "a1288cd700f721c1a119c4f1e8efa234e59caada",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "70d86e355c564b5510fde61361df014f5476c83e",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "372f33ebed747d91870f57c0a2e62884a870bffa",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "bde742b076cbe26ecc89c8c68c76ae076a524d02",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
},
{
"lessThan": "96d47e40bf9db4a9efd5c8fb53287a508d165f14",
"status": "affected",
"version": "60b3013cdaf3fa8a17243ca46b19db3cbe08d943",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/usb/serial/kl5kusb105.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.35"
},
{
"lessThan": "2.6.35",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.259",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.210",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.176",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.143",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.94",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.36",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"affectedData": [
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:10"
],
"defaultStatus": "affected",
"product": "Red Hat Enterprise Linux 10",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:7"
],
"defaultStatus": "affected",
"product": "Red Hat Enterprise Linux 7",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:8"
],
"defaultStatus": "affected",
"product": "Red Hat Enterprise Linux 8",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:9"
],
"defaultStatus": "affected",
"product": "Red Hat Enterprise Linux 9",
"vendor": "Red Hat"
},
{
"cpes": [
"cpe:/o:redhat:enterprise_linux:6"
],
"defaultStatus": "unknown",
"product": "Red Hat Enterprise Linux 6",
"vendor": "Red Hat"
}
],
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: serial: kl5kusb105: fix bulk-out buffer overflow\n\nklsi_105_prepare_write_buffer() is called by the generic write path\nwith the bulk-out buffer and its size (bulk_out_size, 64 bytes). It\nstores a two-byte length header at the start of the buffer and copies\nthe payload from the write fifo starting at buf + KLSI_HDR_LEN, but\npasses the full buffer size as the number of bytes to copy:\n\n count = kfifo_out_locked(\u0026port-\u003ewrite_fifo, buf + KLSI_HDR_LEN,\n size, \u0026port-\u003elock);\n\nWhen the fifo holds at least size bytes, size bytes are copied starting\ntwo bytes into the size-byte buffer, writing KLSI_HDR_LEN bytes past its\nend. Copy at most size - KLSI_HDR_LEN bytes instead, leaving room for\nthe header as safe_serial already does.\n\nWriting bulk_out_size or more bytes to the tty triggers a slab\nout-of-bounds write, observed with KASAN by emulating the device with\ndummy_hcd and raw-gadget:\n\n BUG: KASAN: slab-out-of-bounds in kfifo_copy_out+0x83/0xc0\n Write of size 64 at addr ffff888112c62202 by task python3\n kfifo_copy_out\n klsi_105_prepare_write_buffer [kl5kusb105]\n usb_serial_generic_write_start [usbserial]\n Allocated by task 139:\n usb_serial_probe [usbserial]\n The buggy address is located 2 bytes inside of allocated 64-byte region\n\nThe out-of-bounds write no longer occurs with this change applied."
}
],
"id": "CVE-2026-53194",
"lastModified": "2026-06-30T14:44:27.313",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
},
{
"cvssData": {
"attackComplexity": "HIGH",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.0,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.0,
"impactScore": 5.9,
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"type": "Secondary"
}
]
},
"published": "2026-06-25T09:16:36.850",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0a57320f71941d4e0b1307453c9a1f0939afe666"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/14147b7963685957839c76ba8094924e22777d79"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/372f33ebed747d91870f57c0a2e62884a870bffa"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/60af1fd82983c26604102e63a3fcc822c186cceb"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/70d86e355c564b5510fde61361df014f5476c83e"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/96d47e40bf9db4a9efd5c8fb53287a508d165f14"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/a1288cd700f721c1a119c4f1e8efa234e59caada"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/bde742b076cbe26ecc89c8c68c76ae076a524d02"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://access.redhat.com/security/cve/CVE-2026-53194"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2492703"
},
{
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53194.json"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-787"
}
],
"source": "0b0ca135-0b70-47e7-9f44-1890c2a1c46c",
"type": "Secondary"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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