CVE-2026-53193
HIGHIn the Linux kernel, the following vulnerability has been resolved: ALSA: timer: Forcibly close timer instances at closing When snd_timer object is freed via snd_timer_free() and…
Description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: timer: Forcibly close timer instances at closing
When snd_timer object is freed via snd_timer_free() and still pending snd_timer_instance objects are assigned to the timer object, it tries to unlink all instances and just set NULL to each ti->timer, then releases the resources immediately. The problem is, however, when there are slave timer instances that are associated with a master instance linked to this timer: namely, those slave instances still point to the freed timer object although the master instance is unlinked, which may lead to user-after-free. The bug can be easily triggered particularly when a new userspace-driven timers (CONFIG_SND_UTIMER) is involved, since it can create and delete the timer object via a simple file open/close, while the other applications may keep accessing to that timer.
This patch is an attempt to paper over the problem above: now instead of just unlinking, call snd_timer_close_locked forcibly for each pending timer instance, so that all assigned slave timer instances are properly detached, too. Since snd_timer_close() might be called later by the driver that created that instance, the check of SNDRV_TIMER_IFLG_DEAD is added at the beginning, too.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-53193 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-53193 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-53193. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-53193 in your dependencies?
O3 detects CVE-2026-53193 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.