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Linux Kernel CVE-2026-68201

| EUVDEUVD-2026-55302 HIGH
2026-08-10 Linux GHSA-793q-4mv8-rvwh
7.8
CVSS 3.1 · Vendor: Linux
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Severity by source

Vendor (Linux) PRIMARY
7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
7.0 HIGH

Race condition requires winning a precise timing window (AC:H); local ALSA device access is available to low-privilege audio-group users without root (PR:L, AV:L).

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE
5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat
7.3 HIGH
qualitative

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

5
Analysis Generated
Aug 14, 2026 - 03:36 vuln.today
CVSS changed
Aug 13, 2026 - 23:37 NVD
7.8 (HIGH)
Patch available
Aug 10, 2026 - 14:18 EUVD
CVE Published
Aug 10, 2026 - 12:00 cve.org
HIGH 7.8
CVE Published
Aug 10, 2026 - 12:00 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

ALSA: timer: drain a slave's callback before its master detaches it

snd_timer_close_locked() drains the closing instance's own in-flight callback (IFLG_CALLBACK) before freeing it, but not its slaves'. When a master instance is closed, remove_slave_links() clears each slave's ->timer; the slave's own close then reads timer == NULL and takes the branch that skips the drain entirely (snd_timer_stop_slave() also no-ops on a NULL timer). So a slave whose callback is still running when the master is closed is freed underneath the live callback, leading to use-after-free.

Drain the slaves too before remove_slave_links() severs them. snd_timer_stop() has already taken this instance off the active list, so no new slave callback can be queued. Take the slaves off the ack list so a pending one can't fire either, then wait for any that is already in flight.

AnalysisAI

Use-after-free in the Linux kernel ALSA timer subsystem allows a local low-privileged attacker to corrupt kernel memory by exploiting a race condition during master-slave timer instance teardown. When a master timer closes, slave callback draining is skipped, causing the slave struct to be freed while its callback executes in parallel - a classic UAF primitive with potential for local privilege escalation. EPSS is low at 0.21% (11th percentile), no KEV listing exists, and no public exploit code has been identified at time of analysis, but patched stable kernel releases are available.

Technical ContextAI

The ALSA (Advanced Linux Sound Architecture) timer subsystem implements a master-slave relationship between timer instances. In snd_timer_close_locked(), the closing code drains the master instance's own in-flight IFLG_CALLBACK flag but omits draining any slave instances' callbacks before invoking remove_slave_links(). Once remove_slave_links() clears each slave's ->timer pointer to NULL, the slave's subsequent close path branches on timer == NULL and skips its own drain; snd_timer_stop_slave() likewise no-ops on a NULL timer. This creates a window where the slave struct is freed while its callback is still executing in a concurrent thread, producing a use-after-free - a condition that maps to CWE-416 despite the source listing CWE as N/A. The fix drains slave callbacks and removes slaves from the ack list before remove_slave_links() severs the relationship. Affected CPE: cpe:2.3:a:linux:linux:*.

RemediationAI

Upgrade the Linux kernel to a patched stable release: 7.2-rc5 or later on the 7.2 mainline, 7.1.6 or later on the 7.1 stable branch, 6.12.101 or later on the 6.12 LTS branch, or 6.18.42 or later on the 6.18 branch. The four upstream fix commits are available at git.kernel.org/stable/c/ with hashes cd461bcfcdf8d6b6b5365941c1d3859f8bc77aa0, 426c0ff1c433d6030610ad4f9375746dfe931caa, 2b298997786876b225cff2446e11a0fa6f602f6d, and bdefe1346a8e6b8dc8593406dc2617e985fcbcab. Where kernel upgrades are not immediately feasible, restrict access to /dev/snd/timer via udev rules or by removing untrusted users from the audio group - this eliminates the attack surface at the cost of breaking ALSA-dependent audio applications for those users. On server systems where audio is unused, blacklisting the snd_timer module in /etc/modprobe.d/blacklist.conf and rebooting removes the subsystem entirely with no functional impact. NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-68201.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise Desktop 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Not-Affected
SUSE Linux Enterprise High Availability Extension 16.0 Not-Affected

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CVE-2026-68201 vulnerability details – vuln.today

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