# CVE-2026-98265: ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity CVE-2026-98265 is fixed in 37 products on 1 platform, first by DEBIAN-CVE-2026-98265, released October 6, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-98265 - Priority: Routine - CVSS: 4.6 (Moderate) - EPSS: 0.0017 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Oct 6, 2026 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98265 ## Description In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Clamp implicit feedback packet count to URB capacity data_ep_set_params() allocates each data URB for exactly u->packets isochronous frames, so urb->iso_frame_desc[] has u->packets slots and ctx->packets is the driver's only record of that limit. For an implicit feedback sink, snd_usb_queue_pending_output_urbs() overwrites it with the sync source's packet count, which is calculated independently from the capture endpoint's parameters. When that count is larger, prepare_playback_urb() and prepare_silent_urb() can write iso_frame_desc[] past the allocation; their existing bounds limit payload bytes, not the descriptor index. The reproducer uses a high-speed UAC2 device declaring bInterval 1 for implicit feedback capture (8 packets) and bInterval 4 for playback (1 packet). On the first capture completion after the stream starts, it accesses seven descriptors spanning 112 bytes beyond the one-packet URB: BUG: KASAN: slab-out-of-bounds in prepare_playback_urb (sound/usb/pcm.c:1560) Write of size 4 at addr ffff88801e696ad0 by task vhci_rx/178 prepare_playback_urb (sound/usb/pcm.c:1560) prepare_outbound_urb (sound/usb/endpoint.c:340) snd_usb_queue_pending_output_urbs (sound/usb/endpoint.c:501) snd_complete_urb (sound/usb/endpoint.c:1834) __usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1657) usb_hcd_giveback_urb (drivers/usb/core/hcd.c:1741) vhci_rx_loop (drivers/usb/usbip/vhci_rx.c:107) kthread (kernel/kthread.c:436) The buggy address belongs to the object at ffff88801e696a00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes to the right of allocated 208-byte region [ffff88801e696a00, ffff88801e696ad0) Record the allocated packet count per endpoint and clamp both the adopted count and the packet-size copy to it. Fold the Format Type II delimiter into urb_packs before the allocation loop so the recorded limit matches every URB. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | kernel-uek ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-debug-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-doc ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-doc ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-tools ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek-tools ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-devel ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-core ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-core ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-deprecated ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-desktop ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-extra-netfilter ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-usb ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 10 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | kernel-uek64k-modules-wireless ol 9 | 0:6.12.0-208.112.5.el9uek | [ELSA-2026-500572](https://patchblox.com/security/data/fix/linux/elsa-2026-500572.md) | Nov 7, 2026 | | Linux | linux Debian 13.5 (trixie) | 6.12.113-1 | [DEBIAN-CVE-2026-98265](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98265.md) | Oct 6, 2026 | | Linux | linux Debian 14 | 7.2.8-1 | [DEBIAN-CVE-2026-98265](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98265.md) | Oct 6, 2026 | | Linux | linux-6.12 Debian 12.15 (bookworm) | 6.12.113-1~deb12u1 | [DEBIAN-CVE-2026-98265](https://patchblox.com/security/data/fix/linux/debian-cve-2026-98265.md) | Oct 6, 2026 | --- Data as of 2026-11-08T06:59:42Z UTC. 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