{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80971", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.810Z", "datePublished": "2026-09-11T19:42:34.441Z", "dateUpdated": "2026-10-19T08:45:55.974Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:45:55.974Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: bcd2000: clear the URB pointers on disconnect\n\nbcd2000_free_usb_related_resources() frees both URBs and leaves the\npointers behind:\n\n\tusb_kill_urb(bcd2k->midi_out_urb);\n\tusb_kill_urb(bcd2k->midi_in_urb);\n\n\tusb_free_urb(bcd2k->midi_out_urb);\n\tusb_free_urb(bcd2k->midi_in_urb);\n\nThe rawmidi device outlives that call. A substream that is still open\nwhen the device is unplugged reaches bcd2000_midi_send() from the\ntrigger path on close. That function writes to the freed URB and then\nhands it to the USB core:\n\n\tbcd2k->midi_out_urb->transfer_buffer_length = BUFSIZE;\n\t...\n\tret = usb_submit_urb(bcd2k->midi_out_urb, GFP_ATOMIC);\n\nusb_kill_urb() does not stop a later submission either, so a submit that\nraces the disconnect can requeue the URB after it has been reaped.\nmidi_in_urb is exposed the same way: bcd2000_input_complete() resubmits\nit from the completion handler.\n\nKASAN on 7.2.0-rc5 (arm64):\n\n BUG: KASAN: slab-use-after-free in bcd2000_midi_send [snd_bcd2000]\n Write of size 4 at addr ffff00001827d388 by task bpoc/168\n __asan_store4\n bcd2000_midi_send [snd_bcd2000]\n bcd2000_midi_output_trigger [snd_bcd2000]\n snd_rawmidi_kernel_write1\n close_substream.part.0\n Freed by task 168:\n usb_free_urb\n bcd2000_disconnect [snd_bcd2000]\n\n BUG: KASAN: slab-use-after-free in usb_submit_urb\n Read of size 8 at addr ffff00001827d3b8 by task bpoc/168\n\nClear both pointers after freeing and test them on the paths that can\nstill run. Poison the URBs before freeing them: usb_poison_urb() waits\nfor a running completion handler and rejects any later submission, so\nafter it returns the input path is quiesced and only the rawmidi trigger\npath can still reach bcd2000_midi_send(). No unpoison is needed; the\nURBs are freed on the next line.\n\nDiscovered by XBOW, triaged by Baul Lee " } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The UAF is reached locally by USBDEVFS_DISCONNECT (or sysfs unbind) on an already-bound Behringer BCD2000 while /dev/snd/midi* is held, then close; there is no network or packet path. This matches AV:L scoring of analogous USB disconnect UAFs (CVE-2025-40283, CVE-2026-64585); physical unplug is only an extra path.\nAC:L - The attacker opens the rawmidi node, optionally enables active sensing, then issues USBDEVFS_DISCONNECT and close; close_substream deterministically writes the freed URB in bcd2000_midi_send(). Concurrent write versus disconnect is also attacker-driven. No uncontrollable race or layout is required to trigger the UAF.\nPR:L - USBDEVFS_DISCONNECT has no capable() check, only write access to /dev/bus/usb that udev uaccess/plugdev rules grant seat users, and snd_rawmidi_open has no capability gate on /dev/snd/midi*. An unprivileged local account suffices; init-namespace root is not required.\nUI:N - The attacker performs open, disconnect, and close on their own fds against an already-attached BCD2000 (DJ workstation/kiosk). No separate victim action such as plugging a device or clicking is required during exploitation.\nS:U - The slab use-after-free of struct urb and the subsequent usb_submit_urb run entirely in the host kernel. This is ordinary local privilege escalation, not a VM, IOMMU, or sandbox boundary escape.\nC:H - KASAN shows a use-after-free read in usb_submit_urb of the dangling midi_out_urb after usb_free_urb. Reclaiming the URB slab lets the attacker supply URB fields that the USB core then reads, enabling kernel disclosure, as with other heap UAFs.\nI:H - bcd2000_midi_send() writes transfer_buffer_length on the freed URB and then submits it. A reclaimed fake URB plus usb_submit_urb is a heap write and control-flow primitive (completion handler/DMA setup) suitable for hijack, so integrity impact is High.\nA:H - The UAF oopses the kernel (KASAN slab-use-after-free in bcd2000_midi_send and usb_submit_urb). The attacker can repeat connect/disconnect to crash on demand, so availability impact is High." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "sound/usb/bcd2000/bcd2000.c" ], "versions": [ { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "9af08677aa57debaca5b57c8045c52a83d3dd376", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "5a77febac6faf6da40fbb4555f703eeb91b58130", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "3c00004f134fc819f9d9e202c6a64acde0a1f8d0", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "6c07aad8a7c9ef8ebc4d03a964b882123a349a2e", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "eb482a06791d6168beb8c78cc904ac5a5ed96a55", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "7df3194bdb7479cad9199889655a566a2c0c1d1b", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01", "status": "affected", "versionType": "git" }, { "version": "b47a22290d581277be70e8a597824a4985d39e83", "lessThan": "459d3a64766f5ca2f1886daeaf24582831a5f5ab", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "sound/usb/bcd2000/bcd2000.c" ], "versions": [ { "version": "3.16", "status": "affected" }, { "version": "0", "lessThan": "3.16", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.12.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "6.18.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "7.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9af08677aa57debaca5b57c8045c52a83d3dd376" }, { "url": "https://git.kernel.org/stable/c/5a77febac6faf6da40fbb4555f703eeb91b58130" }, { "url": "https://git.kernel.org/stable/c/3c00004f134fc819f9d9e202c6a64acde0a1f8d0" }, { "url": "https://git.kernel.org/stable/c/6c07aad8a7c9ef8ebc4d03a964b882123a349a2e" }, { "url": "https://git.kernel.org/stable/c/eb482a06791d6168beb8c78cc904ac5a5ed96a55" }, { "url": "https://git.kernel.org/stable/c/7df3194bdb7479cad9199889655a566a2c0c1d1b" }, { "url": "https://git.kernel.org/stable/c/b06ebc7fe25a6af4a9f6e4a3d4236a4178ad4b01" }, { "url": "https://git.kernel.org/stable/c/459d3a64766f5ca2f1886daeaf24582831a5f5ab" } ], "title": "ALSA: bcd2000: clear the URB pointers on disconnect", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2026-80971", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-10-16T19:21:35.341329Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:26:36.913Z" } } ] } }