{"id":"CVE-2026-63893","state":"PUBLISHED","title":"thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: property: Reject u32 wrap in tb_property_entry_valid()\n\nentry->value is u32 and entry->length is u16; the sum is performed in\nu32 and wraps.  A malicious XDomain peer can pick\nvalue = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0\nand passes the > block_len check.  tb_property_parse() then passes\nentry->value to parse_dwdata() as a dword offset into the property\nblock, reading attacker-directed memory far past the allocation.\n\nFor TEXT-typed entries with the \"deviceid\" or \"vendorid\" keys this\nlands in xd->device_name / xd->vendor_name and is readable back via\nthe per-XDomain device_name / vendor_name sysfs attributes; the leak\nis NUL-bounded (kstrdup() stops at the first zero byte) and\nuntargeted (the attacker picks a delta, not an absolute address).\nDATA-typed entries are parsed into property->value.data but not\ngenerically surfaced to userspace.\n\nUse check_add_overflow() so a wrapped sum is rejected.","publishedAt":"2026-07-19T14:55:04.288Z","updatedAt":"2026-10-19T20:17:55.146Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"6a63623621639acbb39bc2d9fb09559681716695","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"9fee50c4e1e42f6d3cbe30df584f9f648f626071","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"8d4a758b407ab3de3be86d1ceadfa35d717d30c7","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"5c06a3043ad944f087bb2ae0aae28d820bb9f460","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"31b98e503ecca8077e5247253dd5425ab84bc96d","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"a47784aee77f33f786dc5d7375db821bdae68792","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"01deda0152066c6c955f0619114ea6afa070aaec","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/property.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.15","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/property.c"]}],"references":["https://git.kernel.org/stable/c/6a63623621639acbb39bc2d9fb09559681716695","https://git.kernel.org/stable/c/e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36","https://git.kernel.org/stable/c/9fee50c4e1e42f6d3cbe30df584f9f648f626071","https://git.kernel.org/stable/c/8d4a758b407ab3de3be86d1ceadfa35d717d30c7","https://git.kernel.org/stable/c/5c06a3043ad944f087bb2ae0aae28d820bb9f460","https://git.kernel.org/stable/c/31b98e503ecca8077e5247253dd5425ab84bc96d","https://git.kernel.org/stable/c/a47784aee77f33f786dc5d7375db821bdae68792","https://git.kernel.org/stable/c/01deda0152066c6c955f0619114ea6afa070aaec"],"weaknesses":["CWE-190"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63893.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63893","state":"PUBLISHED","datePublished":"2026-07-19T14:55:04.288Z","dateUpdated":"2026-10-19T20:17:55.146Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.019Z"},"containers":{"cna":{"title":"thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: property: Reject u32 wrap in tb_property_entry_valid()\n\nentry->value is u32 and entry->length is u16; the sum is performed in\nu32 and wraps.  A malicious XDomain peer can pick\nvalue = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0\nand passes the > block_len check.  tb_property_parse() then passes\nentry->value to parse_dwdata() as a dword offset into the property\nblock, reading attacker-directed memory far past the allocation.\n\nFor TEXT-typed entries with the \"deviceid\" or \"vendorid\" keys this\nlands in xd->device_name / xd->vendor_name and is readable back via\nthe per-XDomain device_name / vendor_name sysfs attributes; the leak\nis NUL-bounded (kstrdup() stops at the first zero byte) and\nuntargeted (the attacker picks a delta, not an absolute address).\nDATA-typed entries are parsed into property->value.data but not\ngenerically surfaced to userspace.\n\nUse check_add_overflow() so a wrapped sum is rejected."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"6a63623621639acbb39bc2d9fb09559681716695","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"9fee50c4e1e42f6d3cbe30df584f9f648f626071","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"8d4a758b407ab3de3be86d1ceadfa35d717d30c7","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"5c06a3043ad944f087bb2ae0aae28d820bb9f460","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"31b98e503ecca8077e5247253dd5425ab84bc96d","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"a47784aee77f33f786dc5d7375db821bdae68792","versionType":"git"},{"version":"cdae7c07e3e3509eaabc18c1640a55dc5b99c179","status":"affected","lessThan":"01deda0152066c6c955f0619114ea6afa070aaec","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/property.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.15","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.15","versionType":"semver"},{"version":"5.10.259","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.210","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.93","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.35","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.12","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/thunderbolt/property.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/6a63623621639acbb39bc2d9fb09559681716695"},{"url":"https://git.kernel.org/stable/c/e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36"},{"url":"https://git.kernel.org/stable/c/9fee50c4e1e42f6d3cbe30df584f9f648f626071"},{"url":"https://git.kernel.org/stable/c/8d4a758b407ab3de3be86d1ceadfa35d717d30c7"},{"url":"https://git.kernel.org/stable/c/5c06a3043ad944f087bb2ae0aae28d820bb9f460"},{"url":"https://git.kernel.org/stable/c/31b98e503ecca8077e5247253dd5425ab84bc96d"},{"url":"https://git.kernel.org/stable/c/a47784aee77f33f786dc5d7375db821bdae68792"},{"url":"https://git.kernel.org/stable/c/01deda0152066c6c955f0619114ea6afa070aaec"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:A - A malicious Thunderbolt XDomain peer (adjacent host, dock, or in-line device on a direct Thunderbolt/USB4 link) delivers crafted PROPERTIES_RESPONSE data that the victim kernel parses during automatic XDomain discovery.\nAC:L - The peer fully controls property entry value/length fields and can reliably craft the u32 wrap (e.g. value=0xffffff00, length=0x100) without races or special memory layout.\nPR:N - Exploitation requires no privileges on the victim system; the attacker only needs to be the connected XDomain peer responding to the kernel-initiated property exchange, with no authentication on that control-plane path.\nUI:N - Once a Thunderbolt XDomain link exists, property fetching and parsing run automatically in the kernel handshake state machine without any additional victim user action at exploitation time.\nS:U - Impact is confined to the victim kernel/userspace boundary (kernel heap disclosure to local sysfs and possible kernel crash); it does not cross VM, IOMMU, or sandbox security boundaries.\nC:H - Integer-wrap bypass enables an out-of-bounds kernel memory read of up to entry->length dwords, which for deviceid/vendorid TEXT properties is copied into world-readable sysfs attributes, disclosing kernel heap contents.\nI:N - The bug is an out-of-bounds read via parse_dwdata(); destination buffers are properly sized kcalloc allocations, so there is no out-of-bounds write or integrity modification of victim kernel structures.\nA:H - Reading from block+0xffffff00 dwords (~4 GB past the allocation) will access unmapped kernel addresses, causing a kernel fault/oops/panic in addition to any information disclosure."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:36:59.715Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.10.259"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"5.15.210"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.12.93"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"6.18.35"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"7.0.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.15","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63893","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:33:06.328646Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","type":"CWE","description":"CWE-190 Integer Overflow or Wraparound"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:17:55.146Z"}}]}}}