# CVE-2026-74503: linux: In the Linux kernel, the following vulnerability has been resolved:  ALSA: timer: Clear SNDRV_TIMER_IFLG_DEAD once th...

CVE-2026-74503 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-74503, released August 16, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-74503
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 15, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  ALSA: timer: Clear SNDRV_TIMER_IFLG_DEAD once the close completes  snd_timer_close_locked() marks an instance with SNDRV_TIMER_IFLG_DEAD and returns early when the flag is already set, but the flag is never cleared again.  A completed close ends in remove_slave_links(), which leaves timeri->timer NULL, so a second close is already harmless through the timer == NULL path; the early return can only be reached by an instance that was opened again in between.  For such an instance the close unlinks nothing, so snd_timer_instance_free() frees an object that is still on timer->open_list_head, still on snd_timer_master_list if it was opened with a slave key, still owns any adopted slaves, and still holds its timer and module references.  snd_seq_timer_open() reopens an instance exactly like that: it retries its fallback open on the same object after a failure that has already run snd_timer_close_locked() internally.  An unprivileged user with access to /dev/snd/timer and /dev/snd/seq can force that failure, since snd_timer_check_master() returns -EBUSY when a pending slave matches the new master's (slave_class, slave_id) key and the target timer has reached max_instances, and SNDRV_TIMER_IOCTL_SELECT with dev_class = SNDRV_TIMER_CLASS_SLAVE keeps the caller-supplied dev_sclass, so a sequencer queue's key can be forged.  The freed instance is afterwards dereferenced by any further snd_timer_open() on that timer, by snd_timer_check_slave(), and by /proc/asound/timers, which faults on the stale ti->owner pointer.  The flag only has to be visible while the close is in progress, which is all its other users need.  Clear it in remove_slave_links(), under the same timer->lock that sets it, once the instance is off every list.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | kernel-uek ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-devel ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-devel ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-doc ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-doc ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-tools ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek-tools ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-206.104.3.3.el9uek | [ELSA-2026-500248](https://patchblox.com/security/data/fix/linux/elsa-2026-500248.md) | Sep 4, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.105-1 | [DEBIAN-CVE-2026-74503](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74503.md) | Aug 16, 2026 |
| Linux | linux Debian 14 | 7.1.8-1 | [DEBIAN-CVE-2026-74503](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74503.md) | Aug 16, 2026 |
| Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.107-1~deb12u1 | [DEBIAN-CVE-2026-74503](https://patchblox.com/security/data/fix/linux/debian-cve-2026-74503.md) | Aug 16, 2026 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.