Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1 ALSA snd_pcm_mmap_data buffer_accessing use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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8.4$0-$5k0.15+

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1. This affects the function snd_pcm_mmap_data of the component ALSA. The manipulation of the argument buffer_accessing results in use after free. This vulnerability is known as CVE-2026-98116. Attacking locally is a requirement. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc1. Affected is the function snd_pcm_mmap_data of the component ALSA. The manipulation of the argument buffer_accessing with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Serialize PCM mmap with buffer reallocation to fix page UAF snd_pcm_hw_params() and snd_pcm_hw_free() guard buffer reallocation with an mmap_count check performed under the PCM stream lock, but the lock is released long before the buffer is actually freed: snd_pcm_sync_stop(), constraint refinement and do_free_pages() all happen in between. snd_pcm_mmap_data(), on the other hand, takes no lock at all: it validates against the old buffer's state and dma_bytes, remaps its pages into the VMA, and only then increments mmap_count. A concurrent mmap() can therefore slip in between the check and the free. remap_pfn_range() installs writable PTEs for the old buffer's pages without taking page references, and the subsequent do_free_pages() returns those pages to the page allocator while the VMA still maps them. This leaves a stale, writable mapping of freed pages: a page-level use-after-free that can be leveraged for local privilege escalation. Make snd_pcm_mmap_data() participate in the buffer-access scheme introduced for hw_params/hw_free: acquire runtime->buffer_accessing before validating and remapping, and release it afterwards. Buffer reallocation already fails with -EBUSY while accessors are active, and the mmap side now fails with -EBUSY while a reallocation is in progress, so the validate/remap sequence and the check/free sequence can no longer interleave. A reproducer that turns this race into a stale writable mapping of the freed DMA buffer pages is available on request.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-98116 since 09/25/2026. The exploitability is told to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/25/2026).

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc2 eliminates this vulnerability. Applying the patch cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5/fd137bf8149bc6460f9b7b1fc292025da04cb9ee/8c1882dfee8f404d118020664b73eb4592172226/9b110a9dcecc59516c77cb3c0caf1f492f75df2d is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc2
Patch: cbc7ec97601d09b74e05e44470fa6b0bcdabf3f5/fd137bf8149bc6460f9b7b1fc292025da04cb9ee/8c1882dfee8f404d118020664b73eb4592172226/9b110a9dcecc59516c77cb3c0caf1f492f75df2d

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-98116 (🔒)
GCVE (CVE): GCVE-0-2026-98116
GCVE (VulDB): GCVE-100-409950

Entryinfo

Created: 09/25/2026 13:10
Changes: 09/25/2026 13:10 (60)
Complete: 🔍
Cache ID: 216::103

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