Linux Kernel up to 6.12.100/6.18.41/7.1.5/7.2-rc4 ALSA Timer snd_timer_interrupt 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-$5k0.00

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.12.100/6.18.41/7.1.5/7.2-rc4. This affects the function snd_timer_interrupt of the component ALSA Timer. Performing a manipulation results in use after free. This vulnerability is cataloged as CVE-2026-68200. The attack must be initiated from a local position. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 6.12.100/6.18.41/7.1.5/7.2-rc4. This affects the function snd_timer_interrupt of the component ALSA Timer. The manipulation 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. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ALSA: timer: don't re-enter an instance callback that is still running The userspace-driven timer (utimer) TRIGGER ioctl calls snd_timer_interrupt() directly with no serialization, so two threads triggering the same utimer can run snd_timer_interrupt() on one snd_timer concurrently. snd_timer_process_callbacks() drops timer->lock around each instance callback and marks the in-flight callback with the single SNDRV_TIMER_IFLG_CALLBACK bit; snd_timer_close_locked() waits on that bit to drain an in-flight callback before freeing the instance. The bit cannot represent two concurrent callbacks: when a second interrupt re-queues an instance whose callback is still running, both run at once, the first to finish clears the bit, and the close-path drain then frees the instance (and its callback_data) while the other callback is still live - a use-after-free reachable by any user able to open /dev/snd/timer, both via a user timer instance and via a sequencer queue timer bound to the utimer. snd_timer_interrupt() sets IFLG_CALLBACK before dropping timer->lock, so a concurrent interrupt already observes it under the lock. Skip re-queuing an instance (and its slaves) to the ack/sack list while its callback is in flight; the accumulated pticks are delivered on the next tick, so no event is lost.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-68200 since 07/30/2026. The exploitability is told 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 08/10/2026).

Upgrading to version 6.12.101, 6.18.42, 7.1.6 or 7.2-rc5 eliminates this vulnerability. Applying the patch 996c24377eea4d4506b7c3ccbbf1e490440b5e0b/1395327a96614885552bae5fbb650e6dd182d49b/c1078130a4cd7e738f4b73afe99b3e68cbfbf884/70d28bfcd6224eed75986b3b987b997e59643fa4 is able to eliminate this problem.

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Productinfo

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Version

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Website

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 6.12.101/6.18.42/7.1.6/7.2-rc5
Patch: 996c24377eea4d4506b7c3ccbbf1e490440b5e0b/1395327a96614885552bae5fbb650e6dd182d49b/c1078130a4cd7e738f4b73afe99b3e68cbfbf884/70d28bfcd6224eed75986b3b987b997e59643fa4

Timelineinfo

07/30/2026 CVE reserved
08/10/2026 +11 days Advisory disclosed
08/10/2026 +0 days VulDB entry created
08/10/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-68200 (🔒)
GCVE (CVE): GCVE-0-2026-68200
GCVE (VulDB): GCVE-100-387549

Entryinfo

Created: 08/10/2026 16:01
Changes: 08/10/2026 16:01 (59)
Complete: 🔍
Cache ID: 216::103

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