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High 7.0Published Sep 25, 2026

CVE-2026-97931ALSA: us122l: Prevent write upgrades for read mappings

Updated under an hour ago ()

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It affects Linux. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

In the Linux kernel, the following vulnerability has been resolved: ALSA: us122l: Prevent write upgrades for read mappings The hwdep mmap callback rejects read-buffer mappings that are initially writable, but leaves VM_MAYWRITE set on mappings created with PROT_READ. A process that can open the hwdep node O_RDWR can later use mprotect() to make the mapping writable. The read allocation begins with struct usb_stream. Its read_size member is used by the fault handler to decide which pages belong to the read buffer. The read VMA intentionally remains expandable because pcm_usb_stream uses mremap() after reading that size. Changing read_size first can therefore map and access pages beyond the allocation. The same member is also consumed by usb_stream_free(), where changing it can make free_pages_exact() release pages outside the allocation. Clear VM_MAYWRITE for read-buffer mappings after rejecting an initially writable VMA. This keeps the separate output-buffer mapping writable while preventing later permission upgrades.

CVSS
7.0 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
Not given
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Linux
NVD analysis
Received
Record last updated
Oct 3, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Linux Linux
linux:linux (from the name)
from 030a07e441296c372f946cd4065b5d831d8dc40c before cbc1f954ce67d739d41d1f0757d29850353ebb6a; from 030a07e441296c372f946cd4065b5d831d8dc40c before becb89036a1320ef0a77da2d27935ac0704345c4; 030a07e441296c372f946cd4065b5d831d8dc40c builds before 6a5f5a5a32c78e67701f1d0f26bc87af68895604; from 030a07e441296c372f946cd4065b5d831d8dc40c before 938e8d6cee8d36f24669dfdcd3717e081eb32d64; from 030a07e441296c372f946cd4065b5d831d8dc40c before 64a87950239867682cde128020e1a47088295e5c; from 030a07e441296c372f946cd4065b5d831d8dc40c before d9c537b14f4982f17b103e3a2cfeee4bee6bc026; 030a07e441296c372f946cd4065b5d831d8dc40c builds before 0eb9dd4774af0ac4d1fd105ef2b0a1f6cec06f2f; from 030a07e441296c372f946cd4065b5d831d8dc40c before 71c610aeb1770302ac9c9e0b9a4ecd37f1311928
CNA record

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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