{"id":"CVE-2026-74499","title":"ALSA: usb-audio: fix OOB write in snd_usbmidi_akai_output()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: fix OOB write in snd_usbmidi_akai_output()\n\nsnd_usbmidi_akai_output() computes its fill-loop bound\n\n\tbuf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - …","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 78dfdeb8d2065524ed5928d6470bf3d3244d1009","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 00cc659a42ac4e94ec880fae2c9bf22fce69c2e8","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < ce949d66607cfb000b8d8d84f80f35a886e72683","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 29a4c29943631301e85f5e9d10f25741bd78e7ba","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 9b22a5c8310b0d55d04f5f0159b913a2fb8b444f","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < b5305a0d0bb8e90a6fc9f88270d5f6c9b8c40081","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 2b7a0f330dd90dd1a7657cec0db019ee1efa4372","Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 0970274613fb463d376211450cab066d34ebfe6a","Linux 2.6.35"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T16:58:49.686471Z"},"published":"2026-08-15","updated":"2026-11-06","sourceUpdated":"2026-11-06T17:05:47.592Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74499","references":[{"url":"https://git.kernel.org/stable/c/78dfdeb8d2065524ed5928d6470bf3d3244d1009"},{"url":"https://git.kernel.org/stable/c/00cc659a42ac4e94ec880fae2c9bf22fce69c2e8"},{"url":"https://git.kernel.org/stable/c/ce949d66607cfb000b8d8d84f80f35a886e72683"},{"url":"https://git.kernel.org/stable/c/29a4c29943631301e85f5e9d10f25741bd78e7ba"},{"url":"https://git.kernel.org/stable/c/9b22a5c8310b0d55d04f5f0159b913a2fb8b444f"},{"url":"https://git.kernel.org/stable/c/b5305a0d0bb8e90a6fc9f88270d5f6c9b8c40081"},{"url":"https://git.kernel.org/stable/c/2b7a0f330dd90dd1a7657cec0db019ee1efa4372"},{"url":"https://git.kernel.org/stable/c/0970274613fb463d376211450cab066d34ebfe6a"}],"tags":["cve.org"],"epss":0.00177,"epssPercentile":0.07265,"ingestedAt":"2026-11-06T18:00:12.551Z","slug":"CVE-2026-74499","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: fix OOB write in snd_usbmidi_akai_output()\n\nsnd_usbmidi_akai_output() computes its fill-loop bound\n\n\tbuf_end = ep->max_transfer - MAX_AKAI_SYSEX_LEN - 1;\n\nas a signed int, so a small device-advertised bulk-OUT max_transfer\nmakes buf_end negative.  The loop guard then compares the u32\nurb->transfer_buffer_length against that negative int: the usual\narithmetic conversion turns buf_end into a large unsigned value, so the\nguard stays true and each iteration keeps appending SysEx framing and\npayload bytes past the end of the URB transfer buffer, which is only\nmax_transfer bytes long.\n\nA USB device that advertises a tiny bulk-OUT endpoint can therefore\ntrigger an attacker-length- and content-controlled heap out-of-bounds\nwrite when a process writes to the created /dev/snd/midiC*D* node.\n\nReturn early when there is no room for even one SysEx, so the loop is\nnever entered with a bound that would wrap.  The loop is the last\nstatement of the function, so bailing out is equivalent to it not\nrunning.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>\n\n## Affected\n\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 78dfdeb8d2065524ed5928d6470bf3d3244d1009`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 00cc659a42ac4e94ec880fae2c9bf22fce69c2e8`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < ce949d66607cfb000b8d8d84f80f35a886e72683`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 29a4c29943631301e85f5e9d10f25741bd78e7ba`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 9b22a5c8310b0d55d04f5f0159b913a2fb8b444f`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < b5305a0d0bb8e90a6fc9f88270d5f6c9b8c40081`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 2b7a0f330dd90dd1a7657cec0db019ee1efa4372`\n- `Linux >= 4434ade8c9334a3ab975d8993de456f06841899e < 0970274613fb463d376211450cab066d34ebfe6a`\n- `Linux 2.6.35`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}