{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63962","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T07:54:57.024Z","datePublished":"2026-07-19T14:55:51.682Z","dateUpdated":"2026-07-20T06:41:42.766Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-07-20T06:41:42.766Z"},"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."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/typec/tcpm/tcpm.c"],"versions":[{"version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","lessThan":"845598b154b9a92e9d279fafafa9405c121ae805","status":"affected","versionType":"git"},{"version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","lessThan":"4505f33dab56c274e82f47f94bf60a8cbf8f4b42","status":"affected","versionType":"git"},{"version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","lessThan":"cbad85b446c06adbc5e5bed565871bb918ce9d32","status":"affected","versionType":"git"},{"version":"4ab8c18d4d67321cc7b660559de17511d4fc0237","lessThan":"3389c149c68c3fea61910ad5d34f7bf3bff44e32","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/typec/tcpm/tcpm.c"],"versions":[{"version":"4.19","status":"affected"},{"version":"0","lessThan":"4.19","status":"unaffected","versionType":"semver"},{"version":"6.12.93","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.35","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.12","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"4.19","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19","versionEndExcluding":"7.1"}]}]}],"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"}}}}