{"api_version":"1","generated_at":"2026-07-21T17:19:32+00:00","cve":"CVE-2026-63962","urls":{"html":"https://cve.report/CVE-2026-63962","api":"https://cve.report/api/cve/CVE-2026-63962.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63962","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63962"},"summary":{"title":"usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()\n\nsvdm_consume_modes() checks pmdata->altmodes against the array size once\nbefore the loop over the count, but forgot to check the bound at every\npoint in the loop.\n\nIn the well-behaved SVDM discovery flow this is harmless because each of\nat most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX\nmodes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX].  But the\nCMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming\nACK with any request the port actually sent.  Once port->partner is set,\nan unsolicited Discover Modes ACK is consumed unconditionally.  A broken\nor malicious port partner can therefore drive altmodes to\nALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra\nDiscover Modes ACK with seven VDOs.  Because the pre-loop check passes,\nthe loop could then writes up to five entries past altmode_desc[].  For\nmode_data_prime the next field in struct tcpm_port is the\npartner_altmode[] pointer array, which then receives partner-chosen\nSVID/VDO bytes.\n\nMove the bound check inside the loop so the array can never be indexed\npast ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner\nsupplies or how the function was reached.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:15","updated_at":"2026-07-20 07:16:41"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/3389c149c68c3fea61910ad5d34f7bf3bff44e32","name":"https://git.kernel.org/stable/c/3389c149c68c3fea61910ad5d34f7bf3bff44e32","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4505f33dab56c274e82f47f94bf60a8cbf8f4b42","name":"https://git.kernel.org/stable/c/4505f33dab56c274e82f47f94bf60a8cbf8f4b42","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/845598b154b9a92e9d279fafafa9405c121ae805","name":"https://git.kernel.org/stable/c/845598b154b9a92e9d279fafafa9405c121ae805","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cbad85b446c06adbc5e5bed565871bb918ce9d32","name":"https://git.kernel.org/stable/c/cbad85b446c06adbc5e5bed565871bb918ce9d32","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63962","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63962","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab8c18d4d67321cc7b660559de17511d4fc0237 845598b154b9a92e9d279fafafa9405c121ae805 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab8c18d4d67321cc7b660559de17511d4fc0237 4505f33dab56c274e82f47f94bf60a8cbf8f4b42 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab8c18d4d67321cc7b660559de17511d4fc0237 cbad85b446c06adbc5e5bed565871bb918ce9d32 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab8c18d4d67321cc7b660559de17511d4fc0237 3389c149c68c3fea61910ad5d34f7bf3bff44e32 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.93 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.35 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.12 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63962","cve":"CVE-2026-63962","epss":"0.002000000","percentile":"0.100200000","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/usb/typec/tcpm/tcpm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"845598b154b9a92e9d279fafafa9405c121ae805","status":"affected","version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","versionType":"git"},{"lessThan":"4505f33dab56c274e82f47f94bf60a8cbf8f4b42","status":"affected","version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","versionType":"git"},{"lessThan":"cbad85b446c06adbc5e5bed565871bb918ce9d32","status":"affected","version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","versionType":"git"},{"lessThan":"3389c149c68c3fea61910ad5d34f7bf3bff44e32","status":"affected","version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/usb/typec/tcpm/tcpm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.19"},{"lessThan":"4.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.93","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.35","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.93","versionStartIncluding":"4.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.35","versionStartIncluding":"4.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.12","versionStartIncluding":"4.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"4.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()\n\nsvdm_consume_modes() checks pmdata->altmodes against the array size once\nbefore the loop over the count, but forgot to check the bound at every\npoint in the loop.\n\nIn the well-behaved SVDM discovery flow this is harmless because each of\nat most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX\nmodes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX].  But the\nCMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming\nACK with any request the port actually sent.  Once port->partner is set,\nan unsolicited Discover Modes ACK is consumed unconditionally.  A broken\nor malicious port partner can therefore drive altmodes to\nALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra\nDiscover Modes ACK with seven VDOs.  Because the pre-loop check passes,\nthe loop could then writes up to five entries past altmode_desc[].  For\nmode_data_prime the next field in struct tcpm_port is the\npartner_altmode[] pointer array, which then receives partner-chosen\nSVID/VDO bytes.\n\nMove the bound check inside the loop so the array can never be indexed\npast ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner\nsupplies or how the function was reached."}],"providerMetadata":{"dateUpdated":"2026-07-20T06:41:42.766Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/845598b154b9a92e9d279fafafa9405c121ae805"},{"url":"https://git.kernel.org/stable/c/4505f33dab56c274e82f47f94bf60a8cbf8f4b42"},{"url":"https://git.kernel.org/stable/c/cbad85b446c06adbc5e5bed565871bb918ce9d32"},{"url":"https://git.kernel.org/stable/c/3389c149c68c3fea61910ad5d34f7bf3bff44e32"}],"title":"usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63962","datePublished":"2026-07-19T14:55:51.682Z","dateReserved":"2026-07-19T07:54:57.024Z","dateUpdated":"2026-07-20T06:41:42.766Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 16:17:15","lastModifiedDate":"2026-07-20 07:16:41","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63962","Ordinal":"1","Title":"usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_con","CVE":"CVE-2026-63962","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63962","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: tcpm: bound altmode_desc[] per iteration in svdm_consume_modes()\n\nsvdm_consume_modes() checks pmdata->altmodes against the array size once\nbefore the loop over the count, but forgot to check the bound at every\npoint in the loop.\n\nIn the well-behaved SVDM discovery flow this is harmless because each of\nat most SVID_DISCOVERY_MAX SVIDs contributes at most MODE_DISCOVERY_MAX\nmodes, exactly filling altmode_desc[ALTMODE_DISCOVERY_MAX].  But the\nCMDT_RSP_ACK handler in tcpm_pd_svdm() does not correlate an incoming\nACK with any request the port actually sent.  Once port->partner is set,\nan unsolicited Discover Modes ACK is consumed unconditionally.  A broken\nor malicious port partner can therefore drive altmodes to\nALTMODE_DISCOVERY_MAX - 1 via the normal flow, and then send one extra\nDiscover Modes ACK with seven VDOs.  Because the pre-loop check passes,\nthe loop could then writes up to five entries past altmode_desc[].  For\nmode_data_prime the next field in struct tcpm_port is the\npartner_altmode[] pointer array, which then receives partner-chosen\nSVID/VDO bytes.\n\nMove the bound check inside the loop so the array can never be indexed\npast ALTMODE_DISCOVERY_MAX regardless of how many VDOs the partner\nsupplies or how the function was reached.","Type":"Description","Title":"usb: typec: tcpm: bound altmode_desc[] per iteration in svdm_con"}]}}}