{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64479","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.791Z","datePublished":"2026-07-25T08:51:41.006Z","dateUpdated":"2026-08-17T04:56:25.868Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:56:25.868Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()\n\nsnd_seq_event_dup() copies an incoming event into a pool cell and, in\nthe UMP-enabled build, clears the trailing cell->ump.raw.extra word that\nthe memcpy() did not cover.  The guard deciding whether to clear it\ncompares the copied size against sizeof(cell->event):\n\n\tmemcpy(&cell->ump, event, size);\n\tif (size < sizeof(cell->event))\n\t\tcell->ump.raw.extra = 0;\n\nFor a legacy (non-UMP) event, size == sizeof(struct snd_seq_event) ==\nsizeof(cell->event), so the condition is false and the extra word keeps\nstale data.  The cell pool is allocated with kvmalloc() (not zeroed) and\ncells are reused via a free list, so that word holds uninitialised heap\nor leftover event data.\n\nWhen such a cell is delivered to a UMP client (client->midi_version > 0)\nthat set SNDRV_SEQ_FILTER_NO_CONVERT -- so the legacy event reaches it\nunconverted -- snd_seq_read() reads it out as the larger struct\nsnd_seq_ump_event and copies the stale word to user space, a 4-byte\nkernel heap infoleak to an unprivileged /dev/snd/seq client.\n\nCompare against sizeof(cell->ump) instead, so the trailing word is zeroed\nfor every event shorter than the UMP cell."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/core/seq/seq_memory.c"],"versions":[{"version":"6389f2c135311c4ce7c08c3b29145c8f95aacf1f","lessThan":"d7649aa11089a93ea2285c210397aa67e5800766","status":"affected","versionType":"git"},{"version":"d7e2ce72833bb23a82b4201fbed7214cc04a4a8c","lessThan":"a224c84e5d3d35708c082c84ad12d81d90762195","status":"affected","versionType":"git"},{"version":"46397622a3fa8372b8fda0f04b33d16923b03b1b","lessThan":"ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a","status":"affected","versionType":"git"},{"version":"46397622a3fa8372b8fda0f04b33d16923b03b1b","lessThan":"fb1aa5082847b98f44f9c6272aee9d0dca9244f0","status":"affected","versionType":"git"},{"version":"46397622a3fa8372b8fda0f04b33d16923b03b1b","lessThan":"651ba82fe2a144bc7356d940bfd235c3810b0549","status":"affected","versionType":"git"},{"version":"46397622a3fa8372b8fda0f04b33d16923b03b1b","lessThan":"6ded42615fa1f4949925afd0a8a9e1ab3bf96202","status":"affected","versionType":"git"},{"version":"46397622a3fa8372b8fda0f04b33d16923b03b1b","lessThan":"435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4","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/core/seq/seq_memory.c"],"versions":[{"version":"6.5","status":"affected"},{"version":"0","lessThan":"6.5","status":"unaffected","versionType":"semver"},{"version":"6.6.145","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.96","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.39","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.4","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"6.5","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d7649aa11089a93ea2285c210397aa67e5800766"},{"url":"https://git.kernel.org/stable/c/a224c84e5d3d35708c082c84ad12d81d90762195"},{"url":"https://git.kernel.org/stable/c/ea672a9f6cc38f06fe69dd2c257ef8a3d4db179a"},{"url":"https://git.kernel.org/stable/c/fb1aa5082847b98f44f9c6272aee9d0dca9244f0"},{"url":"https://git.kernel.org/stable/c/651ba82fe2a144bc7356d940bfd235c3810b0549"},{"url":"https://git.kernel.org/stable/c/6ded42615fa1f4949925afd0a8a9e1ab3bf96202"},{"url":"https://git.kernel.org/stable/c/435990e25bf1f4af3e6df12a6fbfd1f7ba4a97d4"}],"title":"ALSA: seq: Fix uninitialised heap leak in snd_seq_event_dup()","x_generator":{"engine":"bippy-1.2.0"}}}}