{"api_version":"1","generated_at":"2026-10-20T15:39:21+00:00","cve":"CVE-2026-98773","urls":{"html":"https://cve.report/CVE-2026-98773","api":"https://cve.report/api/cve/CVE-2026-98773.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98773","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98773"},"summary":{"title":"USB: cdc-acm: skip URB restart in port_shutdown if disconnected","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: cdc-acm: skip URB restart in port_shutdown if disconnected\n\nacm_port_shutdown() is called from the tty-port machinery whenever the\nlast user closes the port.  acm_disconnect() sets acm->disconnected and\ncalls tty_port_tty_vhangup(), which eventually triggers port_shutdown().\nAt that point acm_disconnect() has already called acm_poison_urbs() and\nis about to free the control and read URBs.\n\nHowever, acm_port_shutdown() unconditionally calls acm_unpoison_urbs()\nand, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the\nctrlurb and all read URBs.  If the concurrent acm_disconnect() then\nfrees those URBs and their DMA buffers while they are in-flight, the\nresult is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback()\naccessing the freed DMA memory.\n\nFix by checking acm->disconnected after draining the delayed anchor and\nreturning early: if we are in a disconnect path the URBs must remain\npoisoned and must not be resubmitted.\n\nThe early return is placed after the delayed-anchor drain loop because\nthat loop only cancels write-side accounting (wb->use = false and\nautopm counter) and does not touch the hardware path.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:31","updated_at":"2026-10-19 10:19:41"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/420ca35af891d33522cc08504768ccd60a4c450a","name":"https://git.kernel.org/stable/c/420ca35af891d33522cc08504768ccd60a4c450a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9742905d9ed5bf23ebe4c100dec80b6bc50fb522","name":"https://git.kernel.org/stable/c/9742905d9ed5bf23ebe4c100dec80b6bc50fb522","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dc614d6bc991740d41d5a99ac7765c4b675dda88","name":"https://git.kernel.org/stable/c/dc614d6bc991740d41d5a99ac7765c4b675dda88","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a0ed07b5bbb2d8fcef86810453216070691816e7","name":"https://git.kernel.org/stable/c/a0ed07b5bbb2d8fcef86810453216070691816e7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98773","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98773","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 603d5a7110832e10165d21f9a1486399457177de 9742905d9ed5bf23ebe4c100dec80b6bc50fb522 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5d29d7ff8679e5a525f22da467ba33c042e8029b a0ed07b5bbb2d8fcef86810453216070691816e7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f58752ebcb35e156c85cd1a82d6579c7af3b9023 420ca35af891d33522cc08504768ccd60a4c450a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f58752ebcb35e156c85cd1a82d6579c7af3b9023 dc614d6bc991740d41d5a99ac7765c4b675dda88 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d826061aa64cb28089bf4c73e301dd7928662b84 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8fb82e3555a7d56a05d8ef0edee9859f889c0860 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 283f8162cc3c82086537cbc7dc01870dbeb07a91 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected f77f10bc76c2da86b4248269472f6d971e37828b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.12.83 6.12.113 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.24 6.18.56 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.1.175 6.2 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6.136 6.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.19.14 6.20 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.0.1 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.1","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.113 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.56 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.10 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/usb/class/cdc-acm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"9742905d9ed5bf23ebe4c100dec80b6bc50fb522","status":"affected","version":"603d5a7110832e10165d21f9a1486399457177de","versionType":"git"},{"lessThan":"a0ed07b5bbb2d8fcef86810453216070691816e7","status":"affected","version":"5d29d7ff8679e5a525f22da467ba33c042e8029b","versionType":"git"},{"lessThan":"420ca35af891d33522cc08504768ccd60a4c450a","status":"affected","version":"f58752ebcb35e156c85cd1a82d6579c7af3b9023","versionType":"git"},{"lessThan":"dc614d6bc991740d41d5a99ac7765c4b675dda88","status":"affected","version":"f58752ebcb35e156c85cd1a82d6579c7af3b9023","versionType":"git"},{"status":"affected","version":"d826061aa64cb28089bf4c73e301dd7928662b84","versionType":"git"},{"status":"affected","version":"8fb82e3555a7d56a05d8ef0edee9859f889c0860","versionType":"git"},{"status":"affected","version":"283f8162cc3c82086537cbc7dc01870dbeb07a91","versionType":"git"},{"status":"affected","version":"f77f10bc76c2da86b4248269472f6d971e37828b","versionType":"git"},{"lessThan":"6.12.113","status":"affected","version":"6.12.83","versionType":"semver"},{"lessThan":"6.18.56","status":"affected","version":"6.18.24","versionType":"semver"},{"lessThan":"6.2","status":"affected","version":"6.1.175","versionType":"semver"},{"lessThan":"6.7","status":"affected","version":"6.6.136","versionType":"semver"},{"lessThan":"6.20","status":"affected","version":"6.19.14","versionType":"semver"},{"lessThan":"7.1","status":"affected","version":"7.0.1","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/usb/class/cdc-acm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.1"},{"lessThan":"7.1","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.113","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.56","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.10","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.113","versionStartIncluding":"6.12.83","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.56","versionStartIncluding":"6.18.24","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.10","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"7.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.175","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.136","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.1","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: cdc-acm: skip URB restart in port_shutdown if disconnected\n\nacm_port_shutdown() is called from the tty-port machinery whenever the\nlast user closes the port.  acm_disconnect() sets acm->disconnected and\ncalls tty_port_tty_vhangup(), which eventually triggers port_shutdown().\nAt that point acm_disconnect() has already called acm_poison_urbs() and\nis about to free the control and read URBs.\n\nHowever, acm_port_shutdown() unconditionally calls acm_unpoison_urbs()\nand, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the\nctrlurb and all read URBs.  If the concurrent acm_disconnect() then\nfrees those URBs and their DMA buffers while they are in-flight, the\nresult is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback()\naccessing the freed DMA memory.\n\nFix by checking acm->disconnected after draining the delayed anchor and\nreturning early: if we are in a disconnect path the URBs must remain\npoisoned and must not be resubmitted.\n\nThe early return is placed after the delayed-anchor drain loop because\nthat loop only cancels write-side accounting (wb->use = false and\nautopm counter) and does not touch the hardware path."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:25:26.276Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/9742905d9ed5bf23ebe4c100dec80b6bc50fb522"},{"url":"https://git.kernel.org/stable/c/a0ed07b5bbb2d8fcef86810453216070691816e7"},{"url":"https://git.kernel.org/stable/c/420ca35af891d33522cc08504768ccd60a4c450a"},{"url":"https://git.kernel.org/stable/c/dc614d6bc991740d41d5a99ac7765c4b675dda88"}],"title":"USB: cdc-acm: skip URB restart in port_shutdown if disconnected","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98773","datePublished":"2026-10-18T15:48:09.093Z","dateReserved":"2026-09-25T10:25:14.369Z","dateUpdated":"2026-10-19T09:25:26.276Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:31","lastModifiedDate":"2026-10-19 10:19:41","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98773","Ordinal":"1","Title":"USB: cdc-acm: skip URB restart in port_shutdown if disconnected","CVE":"CVE-2026-98773","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98773","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: cdc-acm: skip URB restart in port_shutdown if disconnected\n\nacm_port_shutdown() is called from the tty-port machinery whenever the\nlast user closes the port.  acm_disconnect() sets acm->disconnected and\ncalls tty_port_tty_vhangup(), which eventually triggers port_shutdown().\nAt that point acm_disconnect() has already called acm_poison_urbs() and\nis about to free the control and read URBs.\n\nHowever, acm_port_shutdown() unconditionally calls acm_unpoison_urbs()\nand, when the ALWAYS_POLL_CTRL quirk is set, immediately re-submits the\nctrlurb and all read URBs.  If the concurrent acm_disconnect() then\nfrees those URBs and their DMA buffers while they are in-flight, the\nresult is a use-after-free in acm_ctrl_irq() or acm_read_bulk_callback()\naccessing the freed DMA memory.\n\nFix by checking acm->disconnected after draining the delayed anchor and\nreturning early: if we are in a disconnect path the URBs must remain\npoisoned and must not be resubmitted.\n\nThe early return is placed after the delayed-anchor drain loop because\nthat loop only cancels write-side accounting (wb->use = false and\nautopm counter) and does not touch the hardware path.","Type":"Description","Title":"USB: cdc-acm: skip URB restart in port_shutdown if disconnected"}]}}}