Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3 ALSA snd_seq_event_dup heap-based overflow

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3.2	$0-$5k	1.60

Summaryinfo

A vulnerability identified as problematic has been detected in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3. Affected by this vulnerability is the function snd_seq_event_dup of the component ALSA. The manipulation leads to heap-based overflow. This vulnerability is listed as CVE-2026-64479. The attack must be carried out locally. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3. It has been rated as problematic. This issue affects the function snd_seq_event_dup of the component ALSA. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup() snd_seq_event_dup() copies an incoming event into a pool cell and, in the UMP-enabled build, clears the trailing cell->ump.raw.extra word that the memcpy() did not cover. The guard deciding whether to clear it compares the copied size against sizeof(cell->event): memcpy(&cell->ump, event, size); if (size < sizeof(cell->event)) cell->ump.raw.extra = 0; For a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) == sizeof(cell->event), so the condition is false and the extra word keeps stale data. The cell pool is allocated with kvmalloc() (not zeroed) and cells are reused via a free list, so that word holds uninitialised heap or leftover event data. When such a cell is delivered to a UMP client (client->midi_version > 0) that set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it unconverted -- snd_seq_read() reads it out as the larger struct snd_seq_ump_event and copies the stale word to user space, a 4-byte kernel heap infoleak to an unprivileged /dev/snd/seq client. Compare against sizeof(cell->ump) instead, so the trailing word is zeroed for every event shorter than the UMP cell.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-64479 since 07/19/2026. The exploitation is known to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/25/2026).

Upgrading to version 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch d7649aa11089a93ea2285c210397aa67e5800766/a224c84e5d3d35708c082c84ad12d81d90762195/ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a/fb1aa5082847b98f44f9c6272aee9d0dca9244f0/651ba82fe2a144bc7356d940bfd235c3810b0549/6ded42615fa1f4949925afd0a8a9e1ab3bf96202/435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4 is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.144
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
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• 6.12.88
• 6.12.89
• 6.12.90
• 6.12.91
• 6.12.92
• 6.12.93
• 6.12.94
• 6.12.95
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
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• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 7.1.0
• 7.1.1
• 7.1.2
• 7.1.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.3
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.3
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Heap-based overflow
CWE: CWE-122 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: d7649aa11089a93ea2285c210397aa67e5800766/a224c84e5d3d35708c082c84ad12d81d90762195/ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a/fb1aa5082847b98f44f9c6272aee9d0dca9244f0/651ba82fe2a144bc7356d940bfd235c3810b0549/6ded42615fa1f4949925afd0a8a9e1ab3bf96202/435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64479 (🔒)
GCVE (CVE): GCVE-0-2026-64479
GCVE (VulDB): GCVE-100-383273

Entryinfo

Created: 07/25/2026 19:07
Changes: 07/25/2026 19:07 (59)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

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