CVE-2026-53241

Kernel stack disclosure via truncated UMP event copy

Published Jun 25, 2026 · Updated Jun 25, 2026

Out-of-bounds read in the ALSA sequencer dummy port in Linux Kernel allows local users to read kernel stack data via crafted UMP events. seq_dummy.c copies each event into a legacy-sized snd_seq_event stack temporary but preserves the UMP flag, so subscriber delivery copies a larger UMP packet past that object. Low-privilege local access to the ALSA sequencer and a route through the dummy client are required; copied bytes are limited to adjacent kernel stack contents.

CVSS severity5.5
Medium
EPSS probability0.16%
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 ALSA sequencer dummy port in Linux Kernel allows local users to read kernel stack data via crafted UMP events. seq_dummy.c copies each event into a legacy-sized snd_seq_event stack temporary but preserves the UMP flag, so subscriber delivery copies a larger UMP packet past that object. Low-privilege local access to the ALSA sequencer and a route through the dummy client are required; copied bytes are limited to adjacent kernel stack contents.

The record

CVE
CVE-2026-53241
Published
Jun 25, 2026
Updated
Jun 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 25, 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=32cb23a0f911317cdb5030035e49a204aa86fef5 <2b5ff4db5d7aa5b981d966df02e687f79ad7b311
  2. Affected versionversion=32cb23a0f911317cdb5030035e49a204aa86fef5 <6671a46144f880c5a167930ebb14c12f3d059fe9
  3. Affected versionversion=32cb23a0f911317cdb5030035e49a204aa86fef5 <6676b6063440561db600494049ce7ffb695c8cc4
  4. Affected versionversion=32cb23a0f911317cdb5030035e49a204aa86fef5 <a7ef78a2c536242ccb7a4429da01580b2409bb24
  5. Affected versionversion=6.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=32cb23a0f911317cdb5030035e49a204aa86fef5 <2b5ff4db5d7aa5b981d966df02e687f79ad7b311; version=32cb23a0f911317cdb5030035e49a204aa86fef5 <6671a46144f880c5a167930ebb14c12f3d059fe9; version=32cb23a0f911317cdb5030035e49a204aa86fef5 <6676b6063440561db600494049ce7ffb695c8cc4; version=32cb23a0f911317cdb5030035e49a204aa86fef5 <a7ef78a2c536242ccb7a4429da01580b2409bb24; version=6.10

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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

T1005Data from Local System

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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