{"api_version":"1","generated_at":"2026-07-23T17:21:35+00:00","cve":"CVE-2026-63821","urls":{"html":"https://cve.report/CVE-2026-63821","api":"https://cve.report/api/cve/CVE-2026-63821.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63821","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63821"},"summary":{"title":"wifi: rtw88: usb: fix memory leaks on USB write failures","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtw88: usb: fix memory leaks on USB write failures\n\nWhen rtw_usb_write_port() fails to submit a USB Request Block (URB)\n(e.g., due to device disconnect or ENOMEM), the completion callback is\nnever executed.\n\nCurrently, the driver ignores the return value of rtw_usb_write_port()\nin rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these\nfunctions rely on the completion callback to free the socket buffers\n(skbs) and the transaction control block (txcb), a submission failure\nresults in:\n1. A memory leak of the allocated skb in rtw_usb_write_data().\n2. A memory leak of the txcb structure and all aggregated skbs in\n   rtw_usb_tx_agg_skb().\n\nFix this by checking the return value of rtw_usb_write_port(). If it\nfails, explicitly free the skb in rtw_usb_write_data(), and properly\npurge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb().\n\nThe issue was discovered in practice during device disconnect/reconnect\nscenarios and memory pressure conditions. Tested by verifying normal TX\noperation continues after the fix without regressions.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 12:16:55","updated_at":"2026-07-19 12:16:55"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a","name":"https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681","name":"https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb","name":"https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb","name":"https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f","name":"https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63821","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63821","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 53fed4061a09755de99c89fdc7fae5b794da455f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 200d58c851b8f63f77a05570072dd20f79bc3681 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 8206d173d18ef5a077423119f4e9a93cb3a6f4eb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a82dfd33d1237f6c0fb8a7077022189d1fc7ec98 6b964941bbfe6e0f18b1a5e008486dbb62df440a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.2","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.2 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.144 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.95 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.38 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.3 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63821","cve":"CVE-2026-63821","epss":"0.001570000","percentile":"0.052460000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/net/wireless/realtek/rtw88/usb.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb","status":"affected","version":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98","versionType":"git"},{"lessThan":"53fed4061a09755de99c89fdc7fae5b794da455f","status":"affected","version":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98","versionType":"git"},{"lessThan":"200d58c851b8f63f77a05570072dd20f79bc3681","status":"affected","version":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98","versionType":"git"},{"lessThan":"8206d173d18ef5a077423119f4e9a93cb3a6f4eb","status":"affected","version":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98","versionType":"git"},{"lessThan":"6b964941bbfe6e0f18b1a5e008486dbb62df440a","status":"affected","version":"a82dfd33d1237f6c0fb8a7077022189d1fc7ec98","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/net/wireless/realtek/rtw88/usb.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.2"},{"lessThan":"6.2","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.144","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.95","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.38","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.144","versionStartIncluding":"6.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.95","versionStartIncluding":"6.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.38","versionStartIncluding":"6.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.3","versionStartIncluding":"6.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"6.2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtw88: usb: fix memory leaks on USB write failures\n\nWhen rtw_usb_write_port() fails to submit a USB Request Block (URB)\n(e.g., due to device disconnect or ENOMEM), the completion callback is\nnever executed.\n\nCurrently, the driver ignores the return value of rtw_usb_write_port()\nin rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these\nfunctions rely on the completion callback to free the socket buffers\n(skbs) and the transaction control block (txcb), a submission failure\nresults in:\n1. A memory leak of the allocated skb in rtw_usb_write_data().\n2. A memory leak of the txcb structure and all aggregated skbs in\n   rtw_usb_tx_agg_skb().\n\nFix this by checking the return value of rtw_usb_write_port(). If it\nfails, explicitly free the skb in rtw_usb_write_data(), and properly\npurge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb().\n\nThe issue was discovered in practice during device disconnect/reconnect\nscenarios and memory pressure conditions. Tested by verifying normal TX\noperation continues after the fix without regressions."}],"providerMetadata":{"dateUpdated":"2026-07-19T12:02:18.751Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2b2060c2075a72bc2de43ce5e1b9347d6c5e27bb"},{"url":"https://git.kernel.org/stable/c/53fed4061a09755de99c89fdc7fae5b794da455f"},{"url":"https://git.kernel.org/stable/c/200d58c851b8f63f77a05570072dd20f79bc3681"},{"url":"https://git.kernel.org/stable/c/8206d173d18ef5a077423119f4e9a93cb3a6f4eb"},{"url":"https://git.kernel.org/stable/c/6b964941bbfe6e0f18b1a5e008486dbb62df440a"}],"title":"wifi: rtw88: usb: fix memory leaks on USB write failures","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63821","datePublished":"2026-07-19T12:02:18.751Z","dateReserved":"2026-07-19T07:54:57.014Z","dateUpdated":"2026-07-19T12:02:18.751Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 12:16:55","lastModifiedDate":"2026-07-19 12:16:55","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63821","Ordinal":"1","Title":"wifi: rtw88: usb: fix memory leaks on USB write failures","CVE":"CVE-2026-63821","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63821","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: rtw88: usb: fix memory leaks on USB write failures\n\nWhen rtw_usb_write_port() fails to submit a USB Request Block (URB)\n(e.g., due to device disconnect or ENOMEM), the completion callback is\nnever executed.\n\nCurrently, the driver ignores the return value of rtw_usb_write_port()\nin rtw_usb_write_data() and rtw_usb_tx_agg_skb(). Because these\nfunctions rely on the completion callback to free the socket buffers\n(skbs) and the transaction control block (txcb), a submission failure\nresults in:\n1. A memory leak of the allocated skb in rtw_usb_write_data().\n2. A memory leak of the txcb structure and all aggregated skbs in\n   rtw_usb_tx_agg_skb().\n\nFix this by checking the return value of rtw_usb_write_port(). If it\nfails, explicitly free the skb in rtw_usb_write_data(), and properly\npurge the tx_ack_queue and free the txcb in rtw_usb_tx_agg_skb().\n\nThe issue was discovered in practice during device disconnect/reconnect\nscenarios and memory pressure conditions. Tested by verifying normal TX\noperation continues after the fix without regressions.","Type":"Description","Title":"wifi: rtw88: usb: fix memory leaks on USB write failures"}]}}}