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Review reviewHigh

CVE-2026-63893

Linux

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...

CVSS
8.1
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.07.20
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 8.1

Vulnerability overview

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...

Affected product and versions

Product
Linux
Affected versions
>= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 6a63623621639acbb39bc2d9fb09559681716695, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < e8a0b0a93a6ef958e70b1dd4930beb6dc0026b36, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 9fee50c4e1e42f6d3cbe30df584f9f648f626071, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 8d4a758b407ab3de3be86d1ceadfa35d717d30c7, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 5c06a3043ad944f087bb2ae0aae28d820bb9f460, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 31b98e503ecca8077e5247253dd5425ab84bc96d, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < a47784aee77f33f786dc5d7375db821bdae68792, >= cdae7c07e3e3509eaabc18c1640a55dc5b99c179 < 01deda0152066c6c955f0619114ea6afa070aaec, >= 4.15
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
CWE
Not available