CVE-2026-63893
thunderbolt: property: Reject u32 wrap in tb_property_entry_valid()
Description
In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Reject u32 wrap in tb_property_entry_valid() entry->value is u32 and entry->length is u16; the sum is performed in u32 and wraps. A malicious XDomain peer can pick value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0 and passes the > block_len check. tb_property_parse() then passes entry->value to parse_dwdata() as a dword offset into the property block, reading attacker-directed memory far past the allocation. For TEXT-typed entries with the "deviceid" or "vendorid" keys this lands in xd->device_name / xd->vendor_name and is readable back via the per-XDomain device_name / vendor_name sysfs attributes; the leak is NUL-bounded (kstrdup() stops at the first zero byte) and untargeted (the attacker picks a delta, not an absolute address). DATA-typed entries are parsed into property->value.data but not generically surfaced to userspace. Use check_add_overflow() so a wrapped sum is rejected.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 27, 2026, 5:44 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to a patched version.
- Apply the fix for integer overflow in property validation.
- Use overflow checking for arithmetic operations.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63893.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63893 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63893
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-63893 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63893 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '6a63623621639acbb39bc2d9fb09559681716695', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': 'e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '9fee50c4e1e42f6d3cbe30df584f9f648f626071', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '8d4a758b407ab3de3be86d1ceadfa35d717d30c7', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '5c06a3043ad944f087bb2ae0aae28d820bb9f460', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '31b98e503ecca8077e5247253dd5425ab84bc96d', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': 'a47784aee77f33f786dc5d7375db821bdae68792', 'versionType': 'git'}, {'status': 'affected', 'version': 'cdae7c07e3e3509eaabc18c1640a55dc5b99c179', 'lessThan': '01deda0152066c6c955f0619114ea6afa070aaec', 'versionType': 'git'}], 'programFiles': ['drivers/thunderbolt/property.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/thunderbolt/property.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Reject u32 wrap in tb_property_entry_valid() entry->value is u32 and entry->length is u16; the sum is performed in u32 and wraps. A malicious XDomain peer can pick value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0 and passes the > block_len check. tb_property_parse() then passes entry->value to parse_dwdata() as a dword offset into the property block, reading attacker-directed memory far past the allocation. For TEXT-typed entries with the "deviceid" or "vendorid" keys this lands in xd->device_name / xd->vendor_name and is readable back via the per-XDomain device_name / vendor_name sysfs attributes; the leak is NUL-bounded (kstrdup() stops at the first zero byte) and untargeted (the attacker picks a delta, not an absolute address). DATA-typed entries are parsed into property->value.data but not generically surfaced to userspace. Use check_add_overflow() so a wrapped sum is rejected. Added Reference https://git.kernel.org/stable/c/01deda0152066c6c955f0619114ea6afa070aaec Added Reference https://git.kernel.org/stable/c/31b98e503ecca8077e5247253dd5425ab84bc96d Added Reference https://git.kernel.org/stable/c/5c06a3043ad944f087bb2ae0aae28d820bb9f460 Added Reference https://git.kernel.org/stable/c/6a63623621639acbb39bc2d9fb09559681716695 Added Reference https://git.kernel.org/stable/c/8d4a758b407ab3de3be86d1ceadfa35d717d30c7 Added Reference https://git.kernel.org/stable/c/9fee50c4e1e42f6d3cbe30df584f9f648f626071 Added Reference https://git.kernel.org/stable/c/a47784aee77f33f786dc5d7375db821bdae68792 Added Reference https://git.kernel.org/stable/c/e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36