CVE-2026-31778

Stack disclosure via unterminated ALSA card identifier

Published May 1, 2026 · Updated May 1, 2026

Out-of-bounds read in the Linux Kernel ALSA caiaq driver allows local users to expose stack data via a crafted USB product name. The init_card whitespace-stripping loop accepts 16 non-space bytes into a 16-byte id buffer without reserving room for a null terminator, so copy_valid_id_string scans past the stack buffer. Exploitation requires a local user able to present a USB device with a long non-ASCII, non-space product name; the consequence is disclosure of adjacent stack contents, with no reported write primitive.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux Kernel ALSA caiaq driver allows local users to expose stack data via a crafted USB product name. The init_card whitespace-stripping loop accepts 16 non-space bytes into a 16-byte id buffer without reserving room for a null terminator, so copy_valid_id_string scans past the stack buffer. Exploitation requires a local user able to present a USB device with a long non-ASCII, non-space product name; the consequence is disclosure of adjacent stack contents, with no reported write primitive.

The record

CVE
CVE-2026-31778
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1200
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.31
  2. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <02d9c5b0b5553a391448b6d655262bd829f90234
  3. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3178b62e2e31bab39f63d4c8e54bf4ee0a425627
  4. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3afa2e67f3523a980a2f90fd63c22322ac2b9ce0
  5. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6
  6. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <45424e871abf2a152e247a9cff78359f18dd95c0
  7. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <66194c2575a4f567577ae70b1d7561163ce791a6
  8. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <7594a6464873d90fd229e5b94cdd3b92c9feabed
  9. Affected versionversion=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <a82c1bce2d1299dd3c686a8fe48cf75b79a403c7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.31; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <02d9c5b0b5553a391448b6d655262bd829f90234; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3178b62e2e31bab39f63d4c8e54bf4ee0a425627; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3afa2e67f3523a980a2f90fd63c22322ac2b9ce0; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <45424e871abf2a152e247a9cff78359f18dd95c0; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <66194c2575a4f567577ae70b1d7561163ce791a6; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <7594a6464873d90fd229e5b94cdd3b92c9feabed; version=bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a <a82c1bce2d1299dd3c686a8fe48cf75b79a403c7

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1200Hardware Additions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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