{"cve":"CVE-2026-74499","nvd":{"published":"2026-08-15T13:17:54.863","modified":"2026-08-19T17:21:07.360","status":"Received","description":"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 - 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>","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/00cc659a42ac4e94ec880fae2c9bf22fce69c2e8","https://git.kernel.org/stable/c/0970274613fb463d376211450cab066d34ebfe6a","https://git.kernel.org/stable/c/29a4c29943631301e85f5e9d10f25741bd78e7ba","https://git.kernel.org/stable/c/2b7a0f330dd90dd1a7657cec0db019ee1efa4372","https://git.kernel.org/stable/c/78dfdeb8d2065524ed5928d6470bf3d3244d1009"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:10.689564601+00:00"},"epss":{"cve":"CVE-2026-74499","score":0.00177,"percentile":0.07208,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}