{"cve":"CVE-2026-90220","nvd":{"published":"2026-09-17T17:17:17.440","modified":"2026-10-21T13:20:43.727","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: Don't leak the extension cell pointer in the bounce payload\n\nThe bounce_error_event() embeds the failed event in the bounce payload\nby pointing data.ext.ptr at it.  When that event is a queued\nvariable-length event, its own data.ext.ptr holds the address of its\nfirst extension cell, put there by snd_seq_event_dup().  The payload\ngoes out verbatim through snd_seq_expand_var_event(), so the address\nreaches userspace.\n\nThat is the same address commit 705dd6dcbc0e (\"ALSA: seq: Clear\nvariable event pointer on read\") removed from the event header.  The\nread path still clears it there, just above the call that expands the\npayload.\n\nEmbed a sanitised copy instead, treated exactly as snd_seq_read()\ntreats the header.  A stack copy is enough because delivery is\nsynchronous and snd_seq_event_dup() copies before returning.\n\nAn unprivileged client reaches this by setting SNDRV_SEQ_FILTER_BOUNCE,\nqueueing a variable-length event to a port that does not exist and\nreading the bounce back.  Eight bytes on 64-bit, from its own pool.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/42c3f856d13a91a0d4c302a0c6854813621136db","https://git.kernel.org/stable/c/59e1592d3c270ff4642d5d6dc55c545306eb0693","https://git.kernel.org/stable/c/6e6e471eef1d5d8cb056c7d364023fe048249204","https://git.kernel.org/stable/c/b1e8d40663997aacaa198f37ce6893e07aaba77a"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-90220","score":0.00201,"percentile":0.0982,"date":"2026-10-25"},"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."]}